i dont understand what agrement for services is, but if you have signed a contract, and paid, but you cant proceed owing to changed circumstances on your part, i cant see how you could expect to get any of the money back unless there was something in the agreement you signed about ill health. The only thing i can suggest is to "sell" the contract onto someone else if possible.
I dont know what the agreement or the services is but say its for a gym membership or something, the best thing to do would be transfer it to someone else if possible