Refund policy - Definition of received?

I had a contract with a timeshare resale company in Florida that had a performance guarantee. To recieve the refund the contract stated: The following must be received 30 days prior to the certificate expiration: 1. The original certificate must be redeemed. 2. a written request for credit 3. a signed contract must have been signed.

At 30 days I faxed a written request for credit including the certificate. I also sent a written request and the certificate via certified mail w/return receipt. It was post marked 30 days prior to the certificate expiration date. The company has rejected my claim saying I didn't meet the 30 day deadline.

Do I have any chance in fighting this? It is for $900. What is the best course of action? One issue is I live in CA and the company is in FL.