Telkom still deducting on expired contract

Telkom is deducting money from my account for a contract that ended in January. They started by deducting R70 and when I reversed this payment they deducted R210 last month. This month it went even further by deducting R475.40 How does this make sense as the contract has ended. Especially during these difficult times they have the nerve to rob and ***** from people.