Mtn data shortfall

On the 16th off April 2025 I called into the mtn call center to upgrade my contract... the sales advisor gave me the options on what I have on offer since my deal was a black Friday deal and there were special upgrades for those contracts..the upgrade was done and everything was approved. This month when my data arrive I noticed that I was short of 80 gigs of data . I went In to the mtn oceans mall branch and the lady logged a complaint with a ref number a few days later I got a message to say the query was complete. But I didn't receive the remaining data so I went again and logged another complaint and according to the lady she told me that my contract was taken out with a 3rd party provider which I did nit know about since I dailed mtn call center to upgrade. So we logged another complaint with a ref number and a few days later I got another sms saying complete but haven't received my data as yet. Mtn should have told me that the call center isn't there's and it's a 3rd party I would have canceled my contract with them ...