I have four upper crowns, one is grey, they have lumps at the back, and I have a lisp

when i rang dentist the receptionist was really rude to me and i explained the lumps at the bck she was you got crowns on the front . she was really unprofessional and i was a private patient paid a lot of money to get these..plus my quote was different to the price she made me pay £140 pounds more please help