payment demand

I app**** for a cell phone at MRP via the phone and was told that the Deal was approved and they will deliver <br> the phone the following day at my home address at 10H00 am. I then waited for Hours but no one came.<br> I therefore decided to call MRP and told them that I was waiting for cell phone delivery but no delivery came and told them to cancel the Deal because they failed to keep their promise to me. So I did not receive any cell phone from MRP but they say I owe them calling and sending letters of demand