OnePlus India — one plus 7 mobile handset

I bought one plus 7 phone in july 2019 online from amazon website.. I started getting issues with this phone within a month.. My screen flickers, the volume of the phone while speaking is very high, when i insert earphones i cannot listen to music and if i get a call and detach my earphones the volume is too loud on a minimum level.. I could hear my own echo on the phone, my phone automatically goes on silent. Mode and even when im on a call it opens up any other apps, it hangs as well.. I went to the service center in kandivali they said its software issue and they formated my phone and said i wont be facing any problem later but the problems are increasing!! This phone is a faulty piece and i want it to be replaced.. Within a month when im facing so many problems even when i paid 32999 for this its ridiculous, its not a cheap price.. One plus are providing such faulty pieces which has to be replaced for such problems im facing in such a short period of time. This is like. Fooling around the customers who trusted one plus company.