Discovery has failed me yet again

This is for the gap cover department of discovery. I joined your gap cover with your promotional offer . You then deducted September . You have acknowledged it was done in error. Thank you for that . My issue now is because you had an érror with your system my medical aid and vitality could not be debited. I work with a budget and thats the amount i left to be debited. Non the less because of your error i am penalised by my bank R100 for an upaid debit. How fair is that. It was your error not mine. When i requested my R100 to be paid back your reply is unfortunately you cannot do that. What is the point of acknowledging something but you will not rectify all errors. R100 might not mean much to Discovery but to me it is a hell of alot when i dont have it and to top it off it has made me short for my debits.