Duplicate Transactions on my account

I filled up my car on the of 2nd June for R500. A week later ( 9th June) the same transaction ran again for another R500. What BP did was to deduct money from my account twice!! This is the second time this has happened and someone needs to attend to this. I don't know how many other people have experienced this or failed to notice it. For all we know this has been going on for months! Luckily FNB picked it up and reversed the transaction. I was unable to reverse the previous one. BP I want my money back! I will definitely not fill my car up there anymore!