Call waiting not working for Iphone X

I purshased I phone x last month. Now after one month I cant activate call waiting. Bluetooth is getting disconnected frequently. I tried reseting phone by erasing all content and this does not help Even contacted my service provide and they said all of the service is activated from their end. Imp thing is I dont have a apple store near by me. Anyone please help to get this fixed. I dont want to travel 100 miles for a phone.