problem with seller

[vedratol-2]

Dear all, i have recently bought this item. I had a problem with the buyer on this item and i want to give feedback to the seller. But now i can not do it because this item is not anymore on my list of purchase history. It seems to vanished. Why is that?
Also, I am very concerned because the seller promise 5 years of warranty on this item, and my experience with there communication and resolving problems while receiving an item made me realized that there my be a problem with seller in the future on this product if  somthing goes wrong with it.

Also i have received this item on 15 of September and even then i couldn't activate money back guaranty option.

Kind regards