Unable to blacklist / block mobile device

<p>One of the company's new phones has been lost and I have been trying to blacklist this device so that I can put a claim in with our insurance company. This phone has never been used and is worth R15 000.</p> <p> </p> <p>I sent through the required letters and then reverted to trying to speak with someone at MTN because I had got no joy with them after mailing them for a month. The person I spoke with told me they could firstly not blacklist a device that had not had a sim card inserted, and then also proceeded to tell me she could not pick up the serial number (which is clearly stated on their invoice) on their system.</p> <p> </p> <p>How then MTN, are we supposed to claim for this phone if you are completely unable to assist your customers???</p>