Why won't admin accept my passwords when the site access does?

I started a socialgo network with a techie doing the initial setting-up. He has pulled out - but the account was set up in his name. He asked me to set up another account, and he would transfer the original site to the new account. However, nothing has happened, as far as I can see - and I now can't access admin on the new site - which I could before. I can log in with e-mail/ password - but the admin section won't accept my already-used password. What do I do? I now have no admin access to either the original site or the new site. Can Socialgo answer this, without having to put it out to tender, as it were?