MTN account overcharged and *******.

I am being ****** in broad daylight. MTN is sucking me dry. I have a contract with them of 50GB at R299.00 a month since August 2020, for the past 3 months they have been charging me between 768.00 and 1635.00, claiming that I have incurred those costs because my data has been depleted. Apparently there has been a limit adjustments without my knowledge as I never asked for adjusted or increased limit. Funny enough since August 2020 I never experienced this and I am expected to pay R3500.00. I topup all the time when I run out of data and buy airtime as it does not form part of the contract.

I feel being ****** and taken advantage by MTN.