unhappy with charges of transactions done with positive balance, but had to pay honoring fee

I am so disappointed with this bank. I bought airtime on the 15th July using a app, also swip my card same day at steers. I had positive balance on my account during these transactions. On the 18th July checking my transaction list boom I am charged R90 on each transactions. When I enquire about this hon. Charges I was told that I did transactions on the 16th with negative balance on my account. I am so angry with them because they are forcing me to agree that I used my card on the 16th as it appears on their statement. But I do have smses with the date and time of the transactions which also shows money bring deducted. They are s ok rude to tell me that I must learn to read and understand my statement. I mustn't but while I m low on cash because I will have charges if they okay om my behalf so so rude