Run around for a cellphone claim

I've claimed a lost cellphone from Edgars Wonderpark under Hollard insurance. I blacklisted the phone, network provider requested 2 IMEI numbers since the phone had dual sim. The blacklisting ref number was sent to me. Did affidavit and submitted to the shop. 2 days later I received an SMS requesting me to email the blacklisting ref number again which I did. 3 days later I called the shop to inquire about the claim, I was told the phone is not blacklisted because only one sim is blacklisted and it looks like cell c blacklisted sim 2 and the one that is insured is sim 1. I was instructed to go to cell c shop ask them to write a letter stating that the other sim was inactive, I went to cell c they told me the phone is blacklisted because the primary sim card is blocked, the other sim is just a secondary sim card. Cell c told me to go to the shop and explain something which I do not understand. As it is I really do not know what to do. How do I block the 2nd sim from a phone which is blacklisted? the 2nd sim was inactive for the past 9 months now which network provider do I call to blacklist the phone because the was no sim card used?