No service for ex-Nashua contracts yet still bille

Good day. I got my Vodacom contract through Nashua Mobile. Now that Nashua closed down, my account was transferred to Vodacom. My account is paid up-to-date and is due for renewal in the next few months. My problem is the gadget is giving me problems with the software and other technical things. I tried to get assistance from Vodacare but they turned me away because the phone is not a \Vodacom Supp**** Gadget"as it was supp**** by Nashua. I tried to explain that indeed its not one because it is Nashua supp**** but that did not help. How else can I get assistance please"