Still waiting for copy of contract

I purchased a Iphone 6 from MTN cosmonet at the Glen shopping center in January. It has been 2 months and I am still waiting for a copy of my contract and proof of purchase to keep my warranty in place. Every time I call the phone is NEVER answered and every time I go to the store, either the consultant is not there or they are simply too busy for me to wait for a copy of my contract which was suppose to be emailed to me according to the consultant. I need to send the phone in for repairs but cannot do so until I have proof of purchase.