Yes, I e-mailed them and here was their response and quite concerning that they basically said I was normally responsible for paying the BTC back. Needless to say, I won't be using them again.
PrimeXBT [Support]
Tue, May 7, 7:51 AM (1 day ago)
to me
Dear Trader,
Your open positions at PrimeXBT were liquidated due to insufficient available margin and after settling the liquidation trades your trading account balance was below 0: -0.05836307 BTC
Liquidation occurs when Available Margin on Trading Account drops below 0%. Any open positions are closed by the assets being sold/bought back (depending on if the positions was a Long or a Short) at Market price, and Available Margin is used as collateral to cover any losses. In most cases it is sufficient to keep the remaining balance positive after the liquidation.
However, as with any Market order, during extremely active market hours or times of swift market action, liquidity in order books may be insufficient to close the positions at the trigger price (bid/ask). In such scenarios Slippage can occur, which causes a price gap when closing the positions. Due to such Slippage during times of insufficient liquidity, account balance can become negative, which is what occurred with your positions.
Under normal circumstances, to continue trading at PrimeXBT you would have to cover the debt in your trading account first.
As we appreciate your interest in trading at PrimeXBT we have decided to write off the debt from your trading account at no cost for you. Your account debt has been cleared and reset to 0. You can deposit and continue trading without restrictions.
We recommend to utilise Additional Stop-Loss and/or Take/Profit protection orders to help minimise the risk of such losses and to allow you to lock in profits automatically.
Thank you for being with PrimeXBT.
Thats quite different from the reply i got regarding your issue:
Yes, the problem is resolved now. Yesterday, liquidation stop-out triggers didn't fire on a few accounts due to a technical issue. We have already compensated all accounts that went negative to bring their balance to back to 0. Part of the maintenance earlier today was intended to fix this issue. We have also put additional monitoring on the margin call triggers and will keep them active and in place until we're sure that the problem is fully fixed and won't happen again