disgusting service, something in my burger

To cut a long story short, bad attitude staff, corner of a tomato sauce sachet found in my burger, and a staff member laughing in my face. Then after complaining I get a R300 voucher so I tell Tracy the lady that gave me he voucher that i won't use it at milnerton mcdonalds coz then they will know it's me.. she said I can use it at any mcdonalds..so a few days later I decided to take kids for lunch, so I go to plattekloof mcdonalds, I order and try to pay with the voucher my a very unpleasant lady called Abigail, and she tells me that I can't use the voucher and that I must come back to the store when a manager is on duty, in a very arrogant and snotty attitude. Now what store operates without a manager????? So I ask Tracy in my now furious state, and guess what I'm still waiting on a answer!!! Tracy, sanet, Hendrick? Pass the buck I see..... basically I've had it with mcdonalds and they have lost my family and I as regular clients completely.... Thanks mcdonalds team.....