Housing ociation. Should I be liable to pay rent for a damp property?

I was given a property to rent which I have been in for a few months. It is clear having lived here that there are damp conditions - mould, high humidity, woodworm possible dry rot & leaks due to exterior damage. I was told that the property had previous damp issues due to a leak in the roof which had been rectified (obviously not). I have emails confirming this an after months of pestering & withholding rent I have finally managed to get the housing ociation to investigate. They have confirmed that prior to me moving in the property needed a new roof this was carried out however the damp caused by the previously damaged roof had not been 'aired' out of the property etc. Additionally they have arranged to give me a dehumidifier for a couple of weeks to 'dry' the place out. However again it is more cost for me i.e. electric and i'm having to continue living in the premises! My question is as they have breached there contract/tenancy agreement by offering me the the place in the first instance I do not feel i am liable to pay rent for this property, nor do i feel i should pay for the electric it will cost to rectify these ongoing issues. Do you think i would have a leg to stand on if I was to say that i would not start paying the rent until the accommodation is as stated in their contract i.e. damp free? If so how would i go about it?