Without knowing which domains are involved, it's impossible to give an exact answer, but I'll try.
Assuming Tucows (http://www.opensrs.org
) is your registrar, complain directly to them about the actions of your host.
The Tucows reseller has no right whatsoever to change ownership over a domain name they simply resold to you. Bottom line is, it's your domain.
Tucows may refer you to their reseller to resolve the complaint, but it appears you've already tried that and failed.
Advise Tucows what you've advised us. The rest will fall into place.