Upvote:4
How I would handle it:
If it's OK, you might as well stay. If they still try to charge you after you don't like their rooms and try to leave, call Booking.com customer support.
Upvote:6
When you made your booking, you were presented with the cancellation policy for that booking.
If the booking is fully refundable, then cancel it on the site. You shouldn't be charged, and if you are, contact the booking.com customer service. If they can't fix the situation, dispute the charge with your card issuer.
If the booking is non-refundable, you can't do anything yourself at this stage. You entered a contract, and until you can demonstrate that there is a breach of contract on their end, you can't just cancel the booking. Even if you cancel the card, you remain liable for the sums you committed to pay.
You can contact the booking.com customer service and let them know of your issue. They often have a lot more power (and willingness to be helpful) than some hotels (though not always). Remember that they represent a majority of the income of the hotel, so if they decide the hotel is not trustworthy and just block them from the site, the hotel is going to lose a lot.
If the situation is not resolved at that point, that's where the approach suggested by alamar comes into play: you show up, you find evidence of the issue (or maybe you don't), you complain, and either they fix it or you ask for a refund and go to your plan B (which should be fully cancellable and refundable until that point, of course). Expect resistance from the hotel. Unless it's part of a reputable chain, they will probably not want to refund anything.
There are other variations on refund policies, such as refundable except first night, refundable with a X% penalty, and so on, but the end result is the same.