McDonald's

I work in Wal mart where this chain is located. On several occasions I have gone in to purchase food and or drink. Today I went in ordered my food and told cashier only ketchup and pickle on my sandwich. If I eat onions it sends me to er being allergic to them. Well they had onion on sandwich and the manager yelled out that I didn't send back special order on it. Looking at the receipt there was no special order sent back on it. The cashier that was working repeated to me my order which was correct. It is not my responsibility to make sure cashier or crew makes food correct. The manager was extremely rude as she has been on many visits to this store.