MTN data contract

I'm having billing issues with MTN on my data contract, I signed up for a MTN Choice 50GB package and it apparently expired on 20 November 2020 according to the tweet I received from them today where I was paying R469 and instead of notifying me they decided to bill me R1619 on 02 January 2021 that's over 3 times the normal amount with zero communication...so much for a telecommunications company.