Dropping calls on i phone 6

Has any one else got this problem for the last 2 weeks i have had issues , when i call some one it tages ages to connect the call , then during the call it cuts out i cannot hear the person and they cannot hear me this happens constantly , then when i go to hang up the screen is frozen in the call for about 10 seconds , I tried resoring the phone from back up and then setting up the phone as new , i swapped my sim still the same problem in fact its worse now.

I have arranged for this to be sent to apple for repair , would they replace my phone instead i dont know if this is possible or if any one else has the same issue?