he can always buy another 

From what the management team say, there not under Oppo tho. There are by their own. They produce one hell of a hardware, as u can see from their keynote video. Cyanogenmod is always a software company that do custom ROM for a lots of phone. So One+ reach out to them when they want their software been done hence the CM 11s ROM which is only for Oneplus One phone. The issue now is with India, which oneplus just launch in that particular country. Cyanogenmod had sign an exclusive deal with Miromax to produce a phone under the brand 'Yu'. So when oneplus wants to get into India they stop it with court order. The outcome is that oneplus one sold in India won't be running the CM11s ROM but Color OS just like Oppo one. So that's the problem.

From your phone dialer, :-
- try dialing *#*#4636#*#*
- it will take you to phone settings > phone information > choose "lte/wcdma"

See if it makes your line more stable.