If you lost an ingame item to a glitch, then the item can only be returned if the glitch is valid.
An ingame glitch is only valid if it is fixable and if the recreation steps are known. You can report the recreation steps to a staff member. The staff will get back to you and let you know if the glitch is fixable or not. If you are unaware of how to reproduce the glitch then the glitch is invalid and no items can be returned.
The reason behind this process is that we cannot trust anyone claiming that they lost an item. A lot of people lie about losing ingame items to get free items. We have to be careful when people claim they lost an item so that is why you need to be able to report a valid glitch with the loss. Items don’t just disappear out of nowhere. Glitches that make you lose items are rare but not impossible.