Delhivery — Courier showing delivered but not received

I recently sent my original college documents from Delhi to Guwahati via Delhivery thinking it would be fast and secure since it’s private. Tracking : [protected]. Status showed “delivered on 7 Oct, 2022” but my college has not received my documents nor have they even received a call from the delivery service. It’s been more than a week now and despite placing complaints they have said they will let me know the status and no further follow up on that. I am extremely upset as those were my ORIGINAL college degree documents. Moreover, Delhivery has given no direct customer care number to resolve this issue and their ticket system is as good as useless since response is pathetic. I want this to be escalated further or know the procedure for placing a formal police complaint against this as my whole career is at stake here.