Wrote in pm to Bitcasino and in their tread, added screenshot.
Wait for them to respond, they are active in the forum and for matters like this, they'd be happy to help you out.
Just be patient and they'll be addressing your concern once they've read your complain.
The amount is not really that huge for them not to address it only 1200 Tron but it's still worth it to claim if you are a gambler any amount will do, and besides Tron is a good coin I'm sure it will be taken care of I have not seen a lot of complaints on Bitcasino.io and they have an active campaign here.
It's not just the amount but the customer service which they can provide to any of their customer's complain. It's about dealing with any certain doubts and inconvenience that one has experienced.
I haven't mentioned the amount of TRX because what's more important is that they'll help any complain regardless of the amount. As long as there's no fault from the customer.