Shabby treatment of an old client

During December 2016, I cancelled Get More Services which Cell C has contracted, I was surprised to see my monthly subscription is more, until I was told that Get More has reinstated the subscription, I only need my refund.

Cell C has debited my account on the 20th of December 2018, I incurred some expenses when the debit order bounced, Im an old client of Cell C, I never experienced that, I need refund on the expenditure incurred on bouncing of the debit order.