No slip given for order and food not upto Standard

We got to the drivethru and somebody took our order which was a Snack Burger and 4Zingerwings. After a few seconds someone else came to take the money R50 at the same window, however she left the drive thru till and went somewhere at the back (kitchen) with our money, we just thot she went to find change.A few minutes later our food came. It didnt take long at all i must admit. However, there was no change. When we asked for our change,the lady who had taken our money came back with only a R20 note. We asked where the rest of the change was and she said \ R20 for zingerwings and R10 for snackburger. I asked for the till slip to confirm that Zingerwings were now R20 and she said she hasnt loaded a slip. I then demanded a slip cz as far as i know Zingerwings are R16.90 and not R20. Somebody else used the very same drive thru till (the one that wasnt used before) and we finally got our slip and change. When we got home the bottom roll burger was very was very soggy and the wings were not fresh as i usually get them it was as if they were warmed up from yesterday's batch. Can somebody please make sure that this never happens again.<br> "