Try to export your wallet private keys from your armory wallet.
Try to follow this while armory is running.
- Choose the wallet where you sent the bitcoin
- Click wallet properties
- Look for backup this wallet then click
- Choose the export key list then click the export key lists button.
- Under that screen enable or check these
- Address String
- Private Key (Plain Base58)
- Include Unused (Address Pool)
- at the bottom "Omit spaces in key data" is checked
Now it should show all of your addresses and private keys that you can import to any wallet like Electrum. Since you already have Electrum you can use the sweep feature you can find this feature by going to wallet>private keys>sweep and paste your private key of the address where you sent BTC from cex.io
Update here if the exporting keys are a success or not.