Nobody here knows what happened on an external site. You can email the site and ask them.
Or just let it be, 4000 satoshi is worth US$ 0.02, which is barely enough to cover the transaction fee when you want to send it. "Bitcoin dust" has no practical value.
Yes its a small amount...but for those who are collecting with faucet...it is not that easy to earn even 4000satoshi...you can send them mail about the situation about i doubt any thing would happen...may be u lost in multiply btc option..