[Resolved]  Vivo Mobile India — Mobile audio automatically decrease during calls

Address:

D.no 74-17-6/2A new rtc colony road 2 near autonagr gate

Hi
We have purchased a vivo y91i mobile from the bigc app and paid via cash on June 17 2020.
There were repetitive issues with the device and the volume is suddenly getting minimised automatically during calls and requires frequent restarts .We have visited the vivo store for 4 times in the last 6 months and it works fine for one week after its visit to the vivo store .
Please help us with an exchange for the same as we are exhausted with this issue.