They should be able to have a provision for you to convert back from Euro to LTC so you can withdraw the funds. I mean, you deposited LTC, so it would be more than fair for you to withdraw LTC and not being forced to withdraw the euro, which is not available.
I have seen a similar problem but with another casino. I am not sure why they do that.
Some casinos even have their ToS that users have to withdraw fund with a same cryptocurrency used for deposit, and the reason is they don't want users to do money laundering and use their casino like a mixer.
I really agree with you. If deposited fund in LTC, why don't allow withdrawal in LTC?
While it should be a first given withdrawal choice for users and all platforms must have deposit and withdrawal for a same cryptocurrency, as it's weird if you are only allowed to deposit LTC and not allowed to withdraw LTC.
Withdraw the fund with other options like BTC, Euro are only like extra options, not the main one if I funded my account in LTC.