I did read what you said, in short, EB see you didnt qualify for the ENGEN only fuel as you bought something from another fuel station.
"eB team : Would love to see how you do this without a slip / proof "
Even better, learn the bloody system ! If you look at the credit card details screen, you will see "minimum required payment". If you do one EFT to the credit card bigger than that value, the auto payment is cancelled.
Download the virgin money spot app. An online paying app where you can pay for goods
A nice example, for BF ..... get 10% back on everything that you pay with the app (for BF ONLY).
Nice shops include -> CapeUnionMart