Telkom Not cancelling Contract and takes more money

ACC number *** I have a Contract with Telkom Mobile and my Contract should have ended end of march I send Thru the form to cancel contract beginning of march and again end of march as I never received any conformation. Now They want to deduct R250 from my account where my contract was always R99 per month last month They deducted R222 and I thought that was for the Cancellation amount