Thats true, but when you find it you are supposed to report it to staff. I'm not sure what you did, but I understand it as you used it w/o telling them. If you went to them and let them know it was a glitch then ur ban is completely unjustified in my opinion, but if you hid it from them and used it, thats a justified ban.
I'm not saying its not a justified ban, however this took place in 2018, keep that in mind, and i already talked to every higher up staff about it, if i stopped evading the blacklisted they'd take my unblacklist into consideration but i appealed last year october and still haven't gotten a response which is irritating, i'm not saying my blacklist was false.