Any user can withdraw his/her funds from the contract at any time, even if the DMEX website is down. To do that the user must follow the following steps:
Find the DMEX Base contract (click here for instructions)
Go to the Contract tab
Select the Read Contract tab
Scroll down until you find the availableBalanceOf function
Enter the collateral token address in the first field (0x0 for ETH) and your wallet address in the second input and press the Query button.
You will see a number appear. This is your balance on the contract in WEI (1 ETH = 1 000 000 000 000 000 000 WEI). Copy the number.
Select Write Contract tab at the top
Click on the "Connect to Web3" link and use your MetaMask wallet (or Ledger through MetaMask)
Go to the withdraw function
Enter the token to withdraw in the first field (0x0 for ETH)
Paste the amount copied in step 6
Press Write and press confirm in the MetaMask.
Thats it. You have manually withdrawn your funds from DMEX.