Outrageous pricing for out of contract data

My data only sim contract expired after 3 years. I had neglected to renew because I had forgotten the date and the data was sufficient and I was paying under R400 per month despite the price adjustments over the years. Once my contract expired I was billed R1962 on 1 June 2024. I was shocked and horrified certain this was a mistake. According to the agents my contract had ended and I was not longer entitled to a discount. What discount? This was the contracted amount, nobody informed me of the risks of not renewing on time. Since I fell out of the contracted term would suspending my services not have been a more viable option? How is charging a client 5 times the monthly amount ok? Generally when you cellphone contract or data sim contract ends you are billed month to month the same amount. Mtn somehow got the idea of blindly robbing customers. The only way out of this ridiculous billing is to extend your relationship with these *****sters. I am currently struggling to get my billing correct and my account has gone unpaid since the agent assisting me has gone silent. I have no idea what to do because I am exhausted of being transferred between different departments with no solution. My credit record is being tarnished because of this incident. This is unfair and wrong. How many helpless people have fallen into this trap?