Import from Germany to South Africa

We had an Import from Germany to South Africa on 9th May 2022, after two weeks we asked where our parcel is, and UPS rep**** that the parcel was Hijacked/lost in Transit. They send us all documentation to fill in for a refund as we have paid the full UPS account and our Supplier in Germany. We do have our own Marine Insurance but UPS said they will refund us. It took weeks before they refunded us R7,436.99 of the R16,163.86 paid to UPS and the R63,000 to our Supplier. We had to contact our own Marine Insurance to see if we can still put a claim in as you only have 30 days to report. Now the Insurance (Santam) cannot get any detail from UPS as they refuse to hand over the Case file. They want us to sign a Non-disclosure but we need to disclose the information to our Insurance Broker. The Case number they gave us is not even valid as we cannot trace the Police Station where it was reported, and they refuse to assist the Broker. This is the most terrible service as they take no responsibility for parcels getting lost. Now UPS cannot even say if it was a Hijacking (we need the Driver's statement and name) or a Parcel ******, how on earth are we going clear this matter with no response from them???