Packlink PRO Shipping Platform

Package worth 3500 euros lost 4 months ago, no information.
After two weeks, they just closed the ticket.
Since then I've been desperately trying to get reimbursed for the insurance I took out (I paid extra for this insurance): nobody answers. We end up talking in a chatbox that says it will put us in touch with the right team, but we're never put in touch with anyone.
No response by e-mail either, it's simply scandalous!!