Disatisfied

Since 2021 FNB has been sneakily taking my money, They stopped for a year and are back to it again this year. And every time I query it they tell me the same thing that the merchant put it through late but this happens days or a week later, And then what happens is they make more money on top of that from charges to sort an issue out that should not have happened in the first place. My balance changes twice after I make a purchase and then the same purchase goes off again, Thank God I checked my balance before going to the shop I would have looked like a fool. Please sort this out.