Paradise Boat Rentals No refund on so-called "safety-deposit" Cape Coral, Florida

On April 30th 2011, we rented a "Bowrider 21 deck boat" at "Paradise
boat rentals" in Cape Coral, Florida.

The request for this was made via e-mail through the companys website:
http://www.vacationboats.com/paradise-boat-rentals-cape-coral-florida.html
on January 21st, 2011.

The business owner, Mr. Julius Wellenreiter, charged our credit card with a U$ 500,--(Five hundred) dollar "security deposit". It was part of the contract that this security-deposit should be returned to our credit card account after the rental period.

We returned the boat on the same day (April 30th, 2011). We got written confirmation that we had returned the boat filled up with gas and in perfect condition with no damage done to the vehicle!
We are still in possesion of the contract, the rental agreement and the confirmation described above. Through the monthly reports that we get from our credit card company we can also make proof of our payments to Mr. Wellenreiter as well as of lack of refunding our safety deposit onto our credit account.

Since then, Mr. Wellenreiter has failed to return the U$ 500,-- dollar security
deposit to our credit card account!

We complained to him about this fact via e-mail right after our return to Austria and we were given the answer, that he would check on this issue the very next day, but nothing happend.

I also called the company on the phone on July 2nd 2011, talking to his wife,
Mrs. Wellenreiter, explaining the case to her.
She promissed me to talk to her husband to solve the problem and she promissed to
call us back or to write an e-mail to us, but also, nothing happened.

We wrote another e-mail on July 3rd 2011, but this time we got no responce at all!

So the fact is, that we are now waiting for 3 MONTHS to get our money back...

We would be very thankful if you could help us in solving this problem and bring
it to a better end!
My wife and i are visiting Florida annually since 1988 and we never had a problem like this before!