Poor way of conducting business

On the 05 May an amount of R968.67 was misteriously deducted from my account.I contacted standard bank to query and they were not able to tell me who had deducted this amount.On their side it reflected as if money was revered into my account but the money was actually debitted from my account.I have no debit orders that go off from my account after the 2nd May. After investigation std bank came back to me that it was woolworths that deducted my account.I asked the reason and the bank was not able to advise.I then advised the lady that this was not acceptable and i want a reason as to why Woolworths deducted my account as this is the first time ever that it happned. A day later i was informed by standard bank that a purchase i made on the 29 April a the woolworths in cresta actually did not go through and hence woolworths had to deduct my account. I was not made aware of the reversal and looked at my incontact messages and was only send a message to say that the purchase was made and the amount deducted.no message of a reversal. This is really very unprofessional as i was not even informed of this and that this was going to be the case.This amount was not budgeted for and has left me with only R267 in my bank account for the rest of the month.Which had obviuosly set me back from paying other stuff like petrol etc for the month. I have never heard from woolworths to make me aware of this either which is not acceptable.I know that this was money that they had to deduct but it could have been handled better. Very annoyed customer.