Truworths Birch Acres, Mtn cellphone Issues

I bought a new cellphone at Birch acres Truworths store on the 15th of October only to find that the phone would not charge two weeks later and have over heating issues. I took it to the store and store manager Dikeledi told me they can't give me new phone due to the 7 days waiting period and they have to follow the warranty procedure. I respect that but I don't understand how am I expected to wait for the phone to be repaired or assessed by Mtn in 2 weeks? What must I use in the meantime? Last week Friday I called Mtn center and they told me that Truworths has not sent my phone in to be fixed. How is that my issue? Why must I suffer because I bought cell phone and unfortunately Mtn cellphones are faulty. How can they fix a new phone? At this point I just want my refund back!!!