Cell C unable to blacklist phone

On 3 June my phone was ****** during a smash and grab incident and I called Cell C to alert them that my phone was ****** and I needed an ITC number in order to blacklist the device and open a case. The customer service agent said they were not able to verify my IMEI number even though I had given them both IMEI numbers written on the box of the phone. The following day, I called again and asked them to blacklist the phone, they said a case was logged and that I would receive an ITC number within 48 hrs. I waited and waited, still nothing. I even reached out to them via Twitter to get an update. I eventually received a call on 7 June and was told the case was closed because they cannot pick up the IMEI number of the phone. I was then advised by the Cell C agent to contact the iStore to verify the IMEI, which I did and iStore confirmed that the IMEI number was correct. On 8 June, I went to the Cell C branch in Fourways Mall to get assistance and they had me fill out the blacklist form, I was then given a new reference number and told that I would get an ITC number within 48hrs. Hours later on that day I receive a call from Cell C to tell me that they cannot pick up the IMEI number and there is nothing they can do.

How is this possible when I had been using the number on the phone for months? Where does Cell C think I have been making phone calls from all this time? That number was the only one I had used on the phone.

I need the ITC number to report the phone ******! Now I am unable to open a case and claim with my insurance.

I honestly do not recommend using Cell C, their systems are clearly faulty and they are not able to serve their customers.