Double billing on Petrol Invoice BP M1 OASIS

On the 26th January I filled up my car for an amount of R562.21 at BP M1 Oasis and paid with my debit card which went through straight away. 3 days later on the 29th I got a debit notification of BP M1 Oasis, this time the amount split into two Petrol R522 and oil R39.90 which I could not see on the notification. This made me wonder if this was done purposely since the initial debit was R562.21 and why split the amounts ? I then called BP and was transferred to Andries who immediately put the blame on my bank and told me its not for the first time, this bank* is always making problems for them with the clients. I then called the bank and my bank explained the merchant language and that the retailer might have only banked on that day hence the double debit. I have to know follow the process of lodging a dispute for my bank to reverse the 2nd debit, due to frustration and need of my money immediately I called BP again and asked for the person that does banking, I was kept on hold for almost 15 minutes and hanged up eventually. I called again and some lady answered this time and told me its not their problem I must take it up with my bank and just hanged up! no remorse or caring!