samsung fualty after repair

So i went to samsung care store in rooderpoort to fix my s4 screen cracked at botoom right and left small crack at top right when i handed phone in everything worked they then replaced screen and when i got phone got told my ear reicever does not work and its due to the crack that was on top right corner they said its due to that my phone ear peice doesnt work ...my phone worked with ear peice speaker with a cracked screen they replace screen and then it doesnt and wanna charge me 497 rand for this now this is not right to me they tryna make money as if it worked with a cracked sceen and u put a new screen shouldnt change anything ...im very unsatisfied