Declined transactions being deducted

I am extremely frustrated with FNB BANK On Saturday I tried to buy food and my FNB VISA CARD was declined twice in a row on the Howler machine - less than a minute apart I felt like a ******** and had to use another bank card. The transaction with my Discovery card went through IMMEDIATELY NOW FNB DEDUCTED THE DECLINED TRANSACTIONS TWICE WITHOUT ANY PRODUCT OR SERVIVE from their side I complained with FNB on their FNB CHATLINE the same day. After a few hours FNB REVERSED the transactions. Yet today they deducted the transactions AGAIN!!! with the excuse that the two transactions were pending instead of declined. What disturbed me the most, is that they deducted two duplicated transactions. I am extremely disappointed in FNB!!! In other words they firstly deducted two identical declined transactions. Then they reversed the two declined identical transactions. Now on Tuesday they deducted the two identical transactions AGAIN!!!!!