MTN won't find my contract nor settle my insurance

I'm a current MTN contract holder who acquired one of my MTN devices in Nov 2015. On the acqusition of the phone I also signed for the MTN Insurance and didn't receive a copy of my contract. It so happened that I unfortunately lost my phone on the 29th May 2015, although it was a mission to actually report my phone as ****** at the time due to the recurring MTN strikes, I eventually managed to. After all the hassles of getting a case number and submitting the necessary documents to MTN Ghandi Square, the MTN Consultants advised me that according to their database I didn't sign for any insurance and that they can't find a copy of my contract at the respective branch and their head office. This is a major inconvinience because of their negligence as a service provider. I just need to prove that I actaully signed the contract and the insurance component of the respective contract.