Evri is a terriable company, I would not use them to post an expensive item. I did sell mobile phone on Ebay before and always use Royal Mail special delivery: yes, it's more expensive, but the profit from expensive item can easily cover few pound difference, and I had never got an issue, zero return from customers. If I sell cheap item, then yes, I will consider both RM and EVRI, however I will try to avoid EVRI, they are a pain. If I were you, I will definitely prepare a letter of claim