cellphone blacklisted

Hi , i took up a contract with Telkom and my contract is ending next month. My problem is that during this duration of my contract my Q10 had fault and i took it in for repairs of which they told me in the Jeffreys bay branch that they couldnt fix my phone and gave me another phone of which wasnt brand new and now that phone is blacklisted and a consultant phoned me yesterday and i told her this and her boss told me to just upgrade and get a new phone since my phone isnt working, and also told me that maybe the original owner of this replacement phone reported it ****** and thats why is blacklisted. Been calling the customercare but no luck in receiving help but they want me to upgrade.