Telkom mobiles operating like a bank charging unpaid debit fee

Back in 2017 I took up a contract with Telkom and sales agent seemed more keen to just make a sale and that was it! and he never explained to me the term and conditions of the contract and more specifically the condition regarding the "R 200 unpaid fee" and suddenly when my bill came i was charged monthly subscription with an inclusion of that fee and when I contacted the customer careline they were quick to say "but you should have read your contract" yet I was not event explained these hidden costs, and i told them that i do not have problem committing to the agreed monthly amount but not with undeclared fee which I am forced to pay.