The receptionist created rules to scam me.
The receptionist (a woman with blond hair) tried to scam me by making up rules at late night. During my stay, my guest came over for a few hours during the day since it was a rainy day. The woman at the reception said, "You are not allowed to bring guests over or you have to pay 100 EUR for that". She was lying since she was avoiding eye contact, moving around, picking up stuff, pointing at different objects and mentioned that wasn't her idea to charge me but her colleague.
Then she said, "But I will reduce it to 20 EUR and you have to pay now". At the moment I understood it was a scam yet I had to pay to avoid further conflict which would destroy my whole trip. I checked everywhere on the regulations of the hotel and nowhere mentioned that I have to pay for a visit of a guest during the day.
This experience is one of the worst experiences, 20 EUR is not that big yet I don't want to run into it, disgusting behaviour and unacceptable. I'd love to mention this to make sure other people don't run into the same issue which would turn off their travel experience.
After all, I would NOT recommend this hotel Carlton to anyone who plans to stay here.