Checkers Brackenhurst

My wife was shopping in Checkers, when we got to the till point the cashier was busy in a long conversation with the customer in front of us to the point where the whole transaction was delayed. When we finally got to the front to pay for our purchases the cashier did not even greet or acknowledge us up until we were asked if we required a bag. At the end of the transaction my wife requested to split the payment over the bank card and the credit card. This was however when things went worse, the cashier put the total onto the debit card, which we had specifically asked to split to avoid the overdraft fees. When I realised what had happened we exchanged a shocked look between us and the cashier just proceeded with the next transaction. We then went to the manager to report the situation and as much as she tried to assist it never seemed to phase the cashier and to do a refund would of taken another 3 days on top of this to rectify this issue. This is the first time we have ever had this problem with Checkers and we are shocked by this as usually we get top service. ??