Rentalcars.com a NO GO

Booked for a car to be collected on a recent trip to Lisbon. There was no issue making the booking with my credit card but once I arrived to collect the car from rental agent they refused to give me the car as they had an issue with the expiry of my card. I had to make other arrangements, which were costly. After contacting Rentalcars.com for a refund as I obviously could not make use of my original booking, they informed me that no refund would be issued as the problem was mine. Yet they had no problem taking my booking and money with a less than 6 month expiry on Credit card. Just feel that then the booking should not be allowed if card expiry date will be an issue. Will never use any of these online booking agents again!