Hi ShoxyYT,
Next time, just remember that people who have ranks are able to have nicknames. You sent the mana to MrSco's nickname, who isn't a real person. In the future, I would recommend you to hover over the person in chat, or /msg them, so you can have access to their in-game name. Always send mana to their real, in-game name.
I hope this helps.
Kind regards,
Eureka14, a fellow skyblock player.