Engen Petroleum
Credit card rejected for purchase of electicity

I visited this garage to purchase electricity. The cashier, upon seeing my credit card on the table, informed me that I cannot use my credit card to purchase the electricity and that it is cash only. I find this to be a ridiculous policy and would like to enquire why the store does not have signs to indicate this? I am definately not number 1 @ Engen! The quick shop is supposed to provide convenience, not inconvenience!