Samsung — Galaxy M31 microphone doesn't work properly

Address:

Samsung service center TELERIKSSON GALLERY, sector - 16 , faridabad

Dear sir/ mam,

My name is Barkat Ali. I bought Galaxy M31. My mobile have microphone problem last 2 months. Sometimes there is no sound, sometimes there is cut the sound, now microphone sound is so slow. In calling opposite person say hello hello but my voice not gone properly.
I went to the service center 2 times but she said that there is a network problem. While clear talt with the earphone. There is no issue of network problem in earphones.
They are not solving my problem. My mobile is under extended warranty period.

Samsung service center TELERIKSSON GALLERY, sector - 16, faridabad doesn't solve my problem.
Please solve my problem and repair my phone in extended warranty period.