In the following order and presuming that the TS does actually interfere:

1. Your travel insurance (presuming it covers this)
2. Read the t&c of the prepaid contract carefully (if you haven't). Does it say anything about situations where cancellation might be allowed.
3. Call the property directly (not the 800# & do not speak with reservations). You can try asking for a refund, but you are more likely to achieve positive results if you ask to have the stay rescheduled. Don't ask for a credit because the property has to carry it on its books. Ask to have the dates of the stay changed to specific new dates which you provide (and which are during the same season (high, shoulder, low).

You don't need a lecture, but because many people read these: Don't ever book prepaid unless you've got travel insurance and have read the policy word for word. There's nothing worse than saving a couple of hundred to lose a couple of thousand.