Poor service from Samsung cell repair.

I am/were a very loyal Samsung phone supported but my Samsung A50 phone while under guarantee started producing terrible noise on the speaker and microphone. I booked it in at Samsung for repairs and after 21 working days it were returned with the same horrible sounds. It is now another 14 working days and it is still not repaired. If you call the call centre they say the mother board is faulty and possibly only be repaired in the next 5 working days. If this was my car the engine would have been removed and replaced within 2 working days. How can a simple small electronic board take this long??? Perhaps my family's next phones will not be a Samsung??