Kind of strange an honest service tech working with such a dishonest outfit. I think once he got back to his office and management heard about the situation they hoped you would be desperate enough to start throwing money at the problem. The service tech may have learned of their course and not want to call you and talk to you knowing his company was being dishonest. Don't blame him.

They wouldn't take their replacement part back out if it didn't fix the problem? That's pretty fucking unbelievable.