why when you change the type of cheese on your burger do they charge you $.55 but when you order no cheese they still charge you for the cheese???

I have never had that happen. Agree ask a Manager.

Maybe ask the manager at the location..

the store contacted me and said it was a mistake and i got a free burger yummmmm

This was definitely a mistake made by your server. You can substitute any kind of cheese but to add cheese it is an additional .55¢

Because

That sounds like it should have been a substitute. Maybe it was a mistake by the person when they wrote it down and put it into the computer?

They should not charge you if you don't want Cheese