Although I figure that chances of recovery from these people are very slim, as they are very shady as hell to say the least, try to hit them back with what is stated on their breath-taking withdrawal policy:
https[colon]//marketltd[dot]co/wp-content/uploads/2021/07/Deposit-Withdrawal-Policy-Marketltd[dot]pdf
It refers to a bunch of, non-detailed, withdrawal fees, and handling fees, but states that:
<...> those fees will be deducted from the transferred withdrawal amount.
Although I doubt this will really help, nor that they would honour this statement, it seems like the only plausible thing you could attempt, even if I’m pretty sure it will be in vain.
Just to iterate again: You should not send them any more funds, nor give them control to your PC environment no matter what they say.