MTN refuses to refund of alter my contract even though I have a signed contract.

I upgraded my package from 5GB @ R205 and signed a new contract with Tshego at MTN Northgate for 10GB @R299 on the 23rd October 2018. MTN has been charging me R408 pm for the package that I signed a contract for R299.

I have been querying this with MTN for 2 months (from 23 January 2018) and nothing has been done. MTN refuses to refund me and say it was an error at the store and they do not have a package for 10GB @ R299. They said they will not credit me the difference even though I sent them proof of the contract as well as all the emails from when I took up the contract.

To date I have been overcharged a total of R436.

I then asked them to cancel my contract because the amount they are charging me. In order for MTN to cancel my contract they said I need to pay an amount of +R1336.98.

I have followed up for more than seven (7) times and MTN is just refusing to refund me the fee that I am overcharged by and alter my contract.

The reference number is 1- ********** 1146

The last call I made to MTN was on the 5th March and they are saying they will not refund me even though I have a signed contract that says I am taking up a package for10GB R299. They said they only have a package for 10GB at R408. That is even more expensive than buying prepaid data.

I called MTN retentions and I was on the phone for an hour. The supervisor just told the agent to refer my query to migrations as there is nothing they can do to help. REF ********** 03