Turkcell Installment Phone Freezing and Call Crackling

I bought a mobile phone with installments from Turkcell's Ankara Akyurt Ayik dealer about two weeks ago. From the first days, the phone has been freezing during use, and during calls there is a constant crackling noise, so I cannot talk properly. Because of this problem, I tried to get support, but I cannot reach a clear solution. I am constantly being redirected from one place to another and cannot communicate properly with either the dealer or Turkcell, so the issue remains unresolved. Due to the ongoing technical problem and the fact that I cannot use the phone efficiently, I request that my contract regarding this device be cancelled and the necessary procedures be carried out.