Bad customer service

I would like to express my dissatisfaction with Wimpy Florida Junction

I redeemed a R50 Wimpy voucher and requested to buy a burger and chips of R49 the quick bite meal and added a coffee of which I would have paid for separately. I was charged for a normal cheese burger and the difference i had to pay in was R79 I then requested to please change it to the quick bite meal

The lady who served me became extremely annoyed with me as if I was an irritation and said but I asked you Sir she called her supervisor and they did not want to correct the order saying they already punched in my ebucks Wimpy voucher and they can't do anything about it... I then asked can they not void and redo the order and ill pay the correct balance they both were extremely annoyed.. this was really a bad customer experience and they showed no effort to even attempt to accommodate me in fixing the order.

I honestly never had any issues elsewhere but this was a 1st for me