I paid for 1 empty box unwrapped and 1 luggage wra...

I paid for 1 empty box unwrapped and 1 luggage wrapped. They wrapped 1 the box by accident and i thought it was included so i left to check-in. When they realised they made a mistake, they called me and asked me for extra $15. I told them, i thought it was included. Then they asked me to bring the box back and cut the wrap open.
They were right but it was so unprofessional as they wouldn't be able to use the wrap again, would they?
It is called customer service since they made the mistake.