Cash Back in Petro Card

@EdnaBen

I'd suggest to record it as Cash Back Income (or Other Income).
If needed, you can add a New account.

Left dashboard > Accounting > Chart of Accounts > New > Account Type = Income > Detail Type = Service/Fee Income > Name = Cash Back Income > Save.

Hope this helps!

Sorry i am unable to understand.  

1. Transfer Money from Bank to Petro Card (Bank) 200

2. Fuel Expense = 100

3. Cash Back = 10

4. Petro Card Balance = 110

If i create a new  income account won't it come under taxable thing.  How do i record it so that my Petro Card Bank balance shows the actual amount in my PetroCard.

Thanks in advance.

@EdnaBen

Just like you have distribution account for expenses, you also have distribution account for cash back item which is normally categorized as business income. So accounting $10 as Cash Back Income will add to your Fuel Card account.
In your Petro Fuel Debit Bank account with the following three transactions, you should have $110 ending balance.
($200 transfer payment - $100 expense + $10 income = $110 balance).