Bad service by BP vrededorp

On saturday 21/ 5 i was charged R450 for R150 fuel by Nelson and was told it was declined it will reverse to my bank account Not to warry 3 hour later still nothing reversed went back to see them and was told to give it time till Sunday 22/5. I went to the garage on 22/5 and was then told that i now have to first submit my bank statement before my money could be paid back to me. But on 21/5 when i was there nothing was mentioned. Is this the way BP treats customers that has been using the service for years.