Bad service from Mr price

I bought the contract phone Mint Emerald phone from Mr Price shop telephonically. Model emerald M 55CRD colour black. IMECI 1. ********** ********** 2 IMEI 2. ********** ********** 0 . S/N : X ********** 05066. That they delivered the phone on 19 March 2018 at home. I wanted to use the old number and wants that they port my number. They agreed that they will port the number within 2 day. That since then to date, Mr Price haven’t port the number. That since I requested the phone to be port, the old phone is not working. I contacted Mr Price several times and also went to Mr Price shop in Benoni and they did not assist instead the person who assisted was rude. I told Mr Price to cancel as I was not using the number actively but they advised that they will charge me R500.00 for cancelling. . I wants Mr Price to fix the problem or they take their phone and give me my number back