Over a year and a half ago I bought a back accessory for my skin and every time I use it it doesn't let me play on servers or worlds

Every time I enter a server or world with the item on my back, it won't let me in and kicks me out

I would like compensation for all the time I have not been able to play or at least a refund

I've always loved Minecraft and this isn't the first time something like this has happened to me