Being charged for their mistake which I learnt to live with for months.

I have been witb Telkom for a good 2 years and on the first month they did not debit my account and I decided to pay via debit order for all this years without any issues with them. Then last month they reinstated the debit and I reversed it and then continued to do the EFT. Now they have R202 on my invoice for the revesed debit order yet for the past 43 months I did not complain about them not debiting my account. I am happy with telkom mobile service and the network is great I am even planning to upgrade again in June but their style of not debiting then debit when it suits them I find it very wrong