FNB Conexis X2 device not working

I got a Conexis X2 phone from FNB, I'm still paying for the phone monthly but the phone is dead, not powering up when charging. I did not drop the phone and it did not get immersed in water, it just stopped working. Phone is still under warranty. Called FNB call center for assistance now and judging by the consultants rude and direct refusal to help me, repairing FNB's bogus cellphones is not as important as selling them. The disappointing fact is that I have several accounts with FNB but they fail to answer a telephone call in a professional manner when it pertains to repairs, I shudder to think what would happen when I call them to process a funeral claim.

Tip: If FNB call center workers did their jobs right I wouldnt have to resort to posting my queries on this platform for assistance.

Kindly please help.