2 Handset installments on my account

Hey guys<br> <br> So i've been with Vodacom for years now. I upgraded my line in April this year. So i know about the 3 months extra if you upgrade when the upgrade is due. But ive noticed that im paying for two handset instalments since April. I've phoned in multiple times being told that i will be contacted because the person on the other line cannot see why i am being billed for 2 handsets and will log a service request and will be contacted within 72 hours. a week later i call in again and quote them my service number just to be told \i cannot find anything on system please hold so that i can log a service request for you"then i never receive another service request number. Please help."""