Thank you all for your advice, I will of course be pushing for a cash refund as essentially I paid for a product/service which I did not receive! I am prepared for the fact that they will most probably offer me credit...but the credit I would be in in would cover my bills for nearly two years and I really don't think its reasonable to do that, seeing as I might want to move (now that I have all this extra money which I was originally paying to Bord Gais!) or change supplier...
Anyway I suppose I will just have to wait and see what the outcome is, I can't imagine it will all go smoothly, especially for my neighbours, who in all honesty I feel so sorry for! I reckon that their apartment will be alot colder from now on...but hey, at least its nearly Summer...