Problem with the landload.

I rent a commercial apartment. When we leave, I checked it out with the renting manager. There is a paper work for the checkout. Since there are a few stains on the carpet and a few that are not very clean, he said he needed to charge me for $125 for professional cleaning and another $100 for shapoo the carpet. Since it is not a big deal, I and he signed the paper work. After that, a few days later, he said the renting office said the carpet is needed to be changed.

I think since the paperword clearly stated that he can only charge me $100+$125 he should not charge me more.

Please kindly advise if they can legally charge me more than that stated in the checkout paperwork.

Thanks a million