Realme - Realme Outgoing call not working and phone is not replaced since bought

I bought Realme C**Y on *th Dec,****. Since I have bought I keep on facing issues of outgoing calls not working for jio sim.

I have submitted my phone * times to the service centre but the issue still persists after software update and motherboard replacement and I want a phone replacement as there is no permanent solution.

Now, they are agreed to replace phone but they are not having stock of the phone and keep on delaying and issue is not yet resolved. My mother is not having any phone and we all know how phone is important in any emergency.

Mob No.-**********