Wrong phone insured at wrond price

I upgraded my package last year Oct to the Premium Red + with the Samsung S8 handset INCLUDING insurance. With this I received a 2nd phone, the J1. My phone fell, and I was told to take it to the nearest Vodacom shop. This was done on 22 June 2018.

I just received a call from Vodacom Repairs saying my phone is NOT insured. I phoned Vodacom Insurance Dpt and was told that there is a mistake. They insured the J1 for R5000 instead of the S8. THE JI IS NOT EVEN WORTH R5000.00. I can buy the J1 for between R1200 and R1599 new. I was then told that they will have to backdate my insurance to cover the S8. This is not acceptable to me, as I took out insurance on the S8 with the upgrade AND how can you insure the J1 for R5000.00 when its not worth that amount of money. If I never had a claim, you would have insured the the J1 for R5000 for the rest of the term. This is NOT RIGHT, You are dishonest to cover a R1300 phone for R5000. And WHY would I insure the secondary, cheap phone on my package instead of my primary phone? This is clearly a mistake on Vodacom side. When I asked to speak to the policy department to sort this out, I was told I CANNOT SPEAK TO THEM, and have to wait for somebody to phone me back. WHY CAN’T I SORT OUT A PROBLEM CAUSED BY VODACOM IN THE FIRST PLACE? Please can this be sorted out as a matter of urgency as I need to know what to do with the damaged phone. I will NOT pay for your mistake.