Check if the agency has a Chartermark or some such bureaucratic "badge". If they have, write a letter to the organising body, copy it before you send it, send the letter signed for delivery, put only the facts of the case, emphasise your husband's committments etc, but be factual. Wait a week or two (it's Easter!). If you have the name of the clerk who spoke to you, put that in. Wait and see, do not worry about being bad mouthed. Do not tell/confide any of these facts to another agency. When you are ready, contact other agencies and go from there. If anybody comments, which they probably will not, be relaxed about it, but not off-hand and say as little as possible about it but something to the effect that "due to your husband being posted to wherever, family commitments prevented you from taking up the post". Email the school, put everything in writing, keep copies of everything you send, explain the situation and emphasise that the agency is well aware of the situation and have told you that they will find a replacement.