Hi and welcome.
It sounds as if the card has been dropped or had an impact with something from what you have said. The first place to try would be your retailer and see if they can order one for you from the wholesaler. It will probably mean changing the whle heatsink/fan assembly which could be expensive. The other thing is to see if you can pick one up off Ebay as there are many that are removed to fit watercooling blocks.