8210 faulty after flashing

i reported this fault some time ago low ring volume with no increase on a 8210 not wishing to have ago at buying flasher cables i took it to a supposedly nokia repair centre who tried to get the phone written off. I took the phone somewhere else to have it flashed, this not curing the fault, he suggested the piezo ringer was faulty we agreed a total price of £20 when i returned it did ring a lot louder, but unfortunately i failed to check all functions, he did do something as i saw it connected to a pc but now i have problems as no signal, wont dial out, lights come on on off at there own accord, operator logo comes and goes.
Help!!!! i'm going to return the phone to him and see what happens i think hes not flashed it correctly as all functions worked b4 apart from low ringing any ideas gratefully received.

Yeah, give it back to him and tell him to get it sorted! Very unprofessional!!!:mad: