This is not correct. My wife did mention on the doorstep that the flat is cold, that we had to put extra clothes on our baby to keep warm over night, as we felt it was unsafe to keep the electrical heaters on in his room. Your wife agreed that is unsafe to keep a heater in the babys room, but just said to close the curtains. Closing a door curtain doesn't resolve the issue. She clearly was not bothered about the issue. Yes, communication is key and we told you! Don't lie to us!
Based on your wifes response we decided, that you are not really asked about the issue of damp and it seems that our complaints are invalid as no one else complained before.
We are not bothered what other people say, you well know that the flat is damp and that the electrical heaters can't get rid of it. All the plates and cups in the cupboard stink of damp, just go down now and smell them. There is no venilation in a basement flat, what do you expect?
You seem like nice people, but the flat is damp and there is no way around it, sorry to have spoilt the party. We don't want any refund, as we did stay and willing to pay for our stay.