I didn't request that you pay additional cleaning fees. Rather than extend your stay, you booked an additional night.
You requested that I give you a room for £12, with no additional fees, which is unreasonable, so I met you half way, to be courteous.
The price of this room is normally around £30-35 per night, so to have it for £12 is completely unreasonable. If you had extended your stay in advance,instead of after check-out, there wouldn't have been additional charges, only the cost of the additional night (which as I said is usually between £30-35, anyways). You still paid way less than the average guest because of a last minute cancelation from the guest who should've been in your room, and still you complain?!?? How cheap do you want a room in Edinburgh? You can't find a dorm bed for that price?!! Ridiculous