Who is managing my domain?
From the sounds of it, nobody. According to
whois, Tucows Domains is the registrar? Then Tucows Domains is the only company with permission to change the nameservers to "renewyourname.net".
Tucows isn't a reseller of OpenSRS, they own it - OpenSRS is the domain wholesale reselling branch of Tucows. Other companies then deal with registering domains and selling them to people and businesses.
So, are you a reseller with OpenSRS? What kind of username and password do you have there? It sounds like the original company gave you an end user login to their reseller account to manage your domain. I.e. the domain is still belonging to their account.
I don't think OpenSRS sell to end users directly. So if you have a reseller account where you pay OpenSRS for some domains and the domain is not in it, they haven't transferred it to you properly. If you don't have a reseller account, you aren't in a position to take ownership of the domain anyway and they can't have transferred it to you.
I guess the original registrant was an OpenSRS reseller, and they haven't handed the domain over to you at all, and are still responsible for it even though they think they aren't, and that OpenSRS is waiting on payment from them to make the domain live again.
Your argument is either to convince them that they haven't transferred it to you. Or to get them to confirm with OpenSRS that they have and it hasn't worked.
The original domain provider denies responsibility.
There is a complaints and disputes procedure, but it doesn't look simple.
The organisation ICANN has the primary oversight of domain ownership on the internet, Tucows adhere to their lengthy dispute resolution protocols. But you aren't really disputing ownership - you and the original company agree who ought to own it, they are just being incompetent.