very rude, unhelpful contracts department

I cancelled my month-to-month contract, and was paying R115 monthly. the last debit order was on the 28th of April after canceling and making a two-month physical payment on the 4th of April. on the 28th of May, R185 went off my account to CellC. the contracts department is very rude, unhelpful. i had two contracts, i cancelled one about 2 years back and now i am cancelling this one too