Well for a start you would have a case against both people. Your previous employer, and also this current one if a contract is not offered for signing. The fact that a job was offered verbally in this situation means that the job is yours. For it to not go through it would have to be under rather extenuating circumstances, which sounds unlikey given that you explained in detail about your previous employment. If there are other references on your resume, they are indeed in deep doo-doo, for they had ample oppurtunity to check these out. A carefully worded letter expressed delivered would be one option. You have to ask yourself though given there apparent lack of commitment and direction whether you want to work for these people. Hope it works out for you mate.