Prepaid Customer expected to pay off contract

In August 2022 started receiving smses that I owe MTN and legal action would be taken against me, it was quite a suprise to me as I always thought I'm a prepaid customer however when I called them to inquire, the customer care service said "apparently my number is on MyChoice Zero, zero rated contract" and i was told those charges are subscriptions and had to dial *155# to cancel those but when i dial, there's actually nothing to unsubscribe from, so It's like we playing games now and had to pay R214.74 for nothing as I didn't want my credit score to be jeopardized because of misunderstanding , I'm extremely disappointed with MTN after so many years of being loyal to them as a customer.