Custom Unbreaking Enchants not working

As the title says, my custom unbreaking enchants aren't working on armour.
I /enchant the armour with unbreaking 25-500 but when testing the armour durability it takes the same amount of hits to break unbreaking 500 than it takes to break unbreaking 3.

Does anyone know how to fix this? It would be highly appreciated as i've been searching for answers/plugins to fix it for hours and haven't found anything.

 

@alexei7 Which plugin are you using for the /enchant command?

 

just the regular /enchant command as i have essentials and enabled enchants over the standard levels in the config.
i have also tried to use other /enchant plugins but they don't fix the problem with the unbreaking.

@KarimAKL

bump

EDIT by Moderator: merged posts, please use the edit button instead of double posting.

 

According to this post I found (which you should totally read), you'd be better off looking for a plugin that supports such high values.

 

Maybe you can set durability to 12127312836