Struggling for assistance since 17 March

I was on a one to one contract with Foshini which was cancelled on 17 March 2016. I went to an MTN store several times already, was asked to buy several sim cards and still unable to do a sim swap. After purchasing the sim cards they advise that the cell number is still on contract and a sim swap can not be done. Foshini as well as the MTN consultants on 173 as well as the RICA department at MTN has confirmed that the number is on prepaid - but at the store they unable to do the SIM swap - called 173 as well not able to do the sim swap - Please assist as I am frustrated speaking to people who are employed but have no knowledge of their job requirements.