I got 2 waterblocks in my chest that i bought like a year ago. so i decided to do /hat with them suddenly i only had 1 waterblock left is there any explanation for this ? and is there a posible refund on my item ?

 

This is a glitch.
If you have evidence, it might be refundable.

 

Yup. I don't think you have a lot of evidence but a mod may logblock that chest so do not put anything in or out of it.