Promotional Data

I Have a contract with MTN , was due for an upgrade in July 2021. I then called in August 2021 to advise the consultant that i will not be upgrading my contract but will be on a month to month from September 2021. I also made her aware that there is promotional data bundles - 2G that i am paying for and would like that to be removed as i dont use them. She tried removing but could not and then logged a call. In less than 2 days i received an SMS to say my call has been resolved and my query is now closed. I called again in September, same process and as indicated above. Now in September 2021, post the expiry of the contract, i just received an invoice with the same bundles that i am paying R 146.00 i called to notify MTN still no success