If you purchased your domain from a provider who has himself purchased from OVH and that does not satisfy you. Then know that it is still possible to get your domain to a new OVH account by approaching OVH.

For the little story :
In our case, at the beginning we answered our former provider within an acceptable time. But once we wanted to transfer our domain to our new host, it has been no longer answer us or make kinds that things are not moving.
For example, it had not validated the mail transfer by telling us that it was us who had to receive it. While the person who receives this email sent by the registers is the administrative contact (evidence to support) and it has always been our old provider. He must know a long time, evidence that led us by boat.
On this we sought advice from our new host on how to restore our field despite this problem. LWS has said that our domain was at OVH (To find out, go to the Whois of your domain) and therefore had to get closer to OVH to retrieve the "Manager" (management domain) our domain (Source : Forum LWS).
For this, we contacted OVH by email (by this page -> Domains, ...) and they told us that we had to use the "Edit administrative contacts, technical and billing for your domain" on their site. We have clarified that the old NIC (the provider who was in the area) and we were unknown OVH told us saying : this is it "xxxxxx-ovh".
Because the expiration date approached, we decided to renew this old provider (just to avoid losing our domain) and oddly it began to respond quickly and positively.
Once the expiration date has been extended, we filled the OVH form (which creates a file number OVH) and sent the document duly filled with the evidence requested, to OVH (in France). We sent this document recommended precaution (this prevents it was pert, we know that when it arrived at its destination and it avoids to steal a copy of identity for example).
Then one day, our field is found in our new provider OVH and it has been losing a customer account.
That's the story. Now to the tutorial to clarify everything.

First to change the contacts for your domain, you must first have an OVH account for your domain will be transferred once your claims processed.
To do this, click on the link "If you do not have an account at ovh, you can create one here".

Once the account (free) created, go to the Whois of your domain and see if the contact information is hidden. Ie, if the email addresses end with "owo.info".
If this is the case, then check the "Old NIC : Unknown" box.
Otherwise, contact technical support of OVH dedicated to domain,... preferably using the email address of the owner of the domain (not owo but the original is in theory the same as that used for registration at your service). OVH ask if you can have the old NIC and tell them the problem you have with your old provider.

Then enter :
Domain : The domain name (that you own) you want to recover to your OVH Manager.
Old nic : (see explanation above).
Your Email : New mail address that will be shown to all contacts on the Whois (Owner, Admin Contact, Technical Contact and Billing Contact). It may be the last and previous prefer a Gmail address (because less restrictive compared to spam) nobody knows (to avoid email address piracy and therefore domain thereafter).
Legal form : A normal person is an Individual.
You : Name / Surname (as rather clear indications). They must exist because otherwise you can not prove that it is you in the future.
New nic : Name of the new OVH account you just created (or had you before for other domains or OVH services).
Once the form is filled, confirm by clicking "OK".

The validation of this form will generate a PDF file and add partially fills a unique file number in the database OVH data. Here's a screenshot of the PDF file printing.
At the moment only the information in the form specified therein. You must then print the document and add the requested information.
Write to pen the date, location, your name, ... and sign the document. Use your real signature because, as indicated in this document, you must include the credentials that correspond to the possessor visible identifiers in Whois.

IMPORTANT : It's very important that the credentials are scanned in good quality, we recommend that you make a copy of the highest quality to ensure that your request isn't denied. This may seem odd, but if the photo on the credential is not good, your request can be refused.

Once the document is complete and evidence photocopied, you will need (as indicated at the top of the document) send the document as evidence by post. OVH address is shown at the bottom of the document, here is a screenshot.
This address is also listed on their website : guides.ovh.com/ToutPaiement
The address is given in the first yellow frame.

OVH does not require you to send the document by registered but we made our own free will because if you think about it, this budget still contains a copy of your proof of identity (identity card for example) and so it is better to avoid this mail is lost or being stolen by a malicious person. You will also get a receipt stating what day the mail he was received by the recipient (OVH in this case). The address on the right was ours, that is why we have hidden.