The promise to double your BTC pretty much guarantees that it is a ponzi scheme or exit scam.

If it is a scam:

• You're not alone
• You have learned a valuable lesson
• It's never too late to invest small amounts regularly. The market is only going up.

I'm guessing that you have to exchange gladiacoin back into BTC in order to withdraw your funds? That's how BitConnect and other ponzi's work; they force you to use a coin and an exchange which they control.

Best bet is to hope other people want to buy into it and you can recover your BTC. Good luck!