Basically it means you cheated the Wynncraft people out of money and still received your in-game purchase anyways.
When you chargeback something via Paypal, the owner of the servers usually have a permaban policy, since you got those crates on your account and your money at the same time.
I was banned, while I had write an mail, while I have bought Crates for 9$ and haven´t become them. Reason -> Chargeback
Just be patient then! :) wait about a month at latest (the mods can get pretty busy sometimes) and if still no reply, then make another one... also make sure to tag the moderator that banned you by doing: @(insert username here)
My problem is, that I have bouth something and don´t see it... When I don´t get my Money back, PayPal will help me. ^^