MTN DATA DISAPPEARS

On 1st June 22 I bought 500mb of data for both my cell numbers through my bank and received a confirmation from MTN that these had been loaded. By today, 4th June both had disappeared despite me not using cellphone data as I am linked to wi fi. I called MTN and was told their systems take 24 hrs to load the usage and I need to call back again a day later! This is just theft of my money. I purchased a further 500mg for one of the numbers and that appears.....