The only communication I would have with them from this point, is to ask them to provide you a copy of the training agreement they are holding you to, and for your signature on that contract. Verbal contracts do not hold up unless there is absolute proof (video or audio recorded). They will not be able to provide you with the document you ask for, and they will know that you know more than they expected. If that doesn't work, one letter from a lawyer will do the trick.