McDonald's George: Atrocious service

I purchased a double quarter pounder with cheese upsized at the McDonald's George Drive-thru. Order total R93.90. Upon returning to the guest house to eat my meal I was dejected to find a small value size burger instead. Atrocious service from this McDonald's outlet. I have never experienced anything like this here before. I was so disappointed and seriously anoiyed. I wish next time the staff will do a better job in ensuring the right order meats the right client.