Disgraceful service

In the drive thru we ordered a sweet chilli twister meal as well as a regular twister meal. The attendant as mentioned above confirmed or order as a twitter and a sweet chilli twister meal and when we tried correcting her she ignored us and we never received a slip. When we received our meal and it was in fact wrong we complained to the manager who then said that we had to go in to pay for the meal. This is quite unacceptable. It was not our mistake and the solution was to inconvenience is even further.