A manager was standing right there and asked us what was going on. My dad told her everything, etc. and pretty soon we got new burgers. The manager claimed she double-checked the food before handing it to us. We figured everything was fine and dandy, so we drove home.
The suck: we get home, sit down to eat... and find out both burgers have mayo and onions. Exactly the opposite of what we asked for. It was nowhere near the end of the world, but the manager claimed to double-check after we handed it back and asked for a fix, so my dad was pissed. He actually stormed out of the house and went back to BK to get a refund and have our burgers fixed. When he got back he told me the manager got snippy with him. Welp!
A bit of an annoyance for me (moreso for him), but no biggie, we'll just go to the McD's right across the street from now on. :) We've never had bad service there and the staff is sweet as can be.