1. This is an excellent letter to write, which would do many lawyers proud. However, you should include an additional line to the effect, that "Failure by you to either supply & install the unit or pay over the costs associated with supplying and installing the unit will result in legal action against you to recoup the monies". Essentially, you need to both give them the option of paying the monies as well as making clear that they will be sued if they do nothing. Essentially, the preferred option, that they supply and install the unit should not be the only one stated in your letter. The company will have insurance issues in dealing with a claim. It may be more cost effective for them either to rectify the damage themselves or else to let a claim be made against their insurance policy. However, you should let them make that decision, not seek to make it for them.
Please RATE the Answer positively so that I may get paid
Very unhlepful - it did not anything to what I had already written.
A shame as in the past I have found your advice most helpful. PLEASE REFUND THE CHARGE YOU MADE