Airtel — airtel 4g - mobile not reachable/ switch off / call forwarded

Address:

410206

I have been using 2 airtel both mobiles are not reachable only on 4g enabled while others trying to call. Had changed new sim card for both handset and still nothing changed. Airtel customer service advice my handset problem but my both handset are iphone8 both of them worked ver well in singapore. So i assume that airtel doesn’t maintain and their band width and they call themselves as fastest network providers... Well they are fooling everyone 😡