Can't recover my BTC by the command.

[NetSailor]

Hi team,

Recently I used the services of a Mixer, specifically with helixmixer.org .
His server was fallen at momen I did the transaction. They told me later that the way to recover my BTC was introducing a command in 'Console' of my Electrum Bitcoin Wallet where I was using to send BTC to him to make sure I didn't phishing. I entered the command they told me and appears a failure message that told me contact with Support. What I have to do for recover my BTC ?

Thanks for your attention.