I resell with tucows, and I do because I've had nightmares with almost every other registrar company (on behalf of clients) out there. OpenSRS (tucows) is one of the easiest to deal with.
What is the domain name? When you do a whois look up on your domain at tucows it usually lists the reseller. Contact them, keep record of it (copy of email) if they don't respond in a couple of days then tucows has a direct contact for that issue.
To Contact Your Service Provider
Locate your service provider's contact information by using the "
Find my Domain Service Provider" tool on the right. If you have problems contacting your service provider you can
go here for assistance.
The email link (ONLY after you have unsuccessfully attempted to contact your provider) is:
Tucows FAQ Center
Some reseller has been assigned to your domain. Start there.. if that doesn't work go through the above, if that doesn't work, let me know and I'll personally help you out if you like.
I hope that helps a bit, it can be a nightmare when a provider decides to fold up shop or someone else buys them out. Chances are that a reseller was bought out by another reseller, that's usually when things get all messy.
All the best, hope that helps a bit...