We paid our loan off with these people 5 yrs ago. We had a lot of simular problems as you folks.As far as the payment thing...we sent the payments, registered mail and made someone sign for it when they recieved it. They pulle d so many scams, or tried to, on us that it wasn't funny. Even after the loan was paid in full, they tried to tell us we owed them more money . If you carry Home Insurance with them ...you might want to check for as better rate also. I did and saved a bundle.
It felt SOOOOOOOOOOOO good to tell them off that last time. They never called back after that.
Good Luck