Can I do anything to get my items back, or require them to respond in a more timely manor than 2 months?

There is a website that allows people to submit a "skin" or "skins" from a popular video game know as CS:GO (counter strike: global offensive). The skins in this game are worth REAL money, proof provided by following this link to a popular site that sells these items for cash. [ https://opskins.com/ ] With little to no research you can clearly see that there are skins ranging in prices from as little as $.03 to well above $10,000. I traded my skins worth around $800 in price to the website in question. [ https://csgolotto.com/duel-arena ] The bot that accepts the trade should then go on and create a flip of a coin where you either win your skins back and double the money or lose everything. The bot however didn't create a flip and they still have $800 worth of my items. I've been told by admins of the site to submit a ticket but based on my peers having the same problems, they have waited as long as 57 days without a response.