Motorola Solutions — Service centre failure in providing proper service

Address:

760004

I submitted my moto g4 plus at a service centre of motorola for screen burn in and phone shutting down repeatedly. They said a software update would fix it and would take few hours. Then they said it required a motherboard replacement. This took 20 days to replace the motherboard. But then when i received my handset i saw similar problems almost as if nothing was done all problems still remains persistent. They said it is normal for thus handset. My warranty is over too now.. What should i do now? This is what serves for service repairs and warranty these days? Such poor performance was not expected from moto g4 plus.