Tracking Unit Account Nightmare

Can Auto and General please advise why I'm paying for a tracking unit under my insurance yet I'm being harrased by Netstar on the side for unpaid monthly fees! I'm now being handed over by them, when I ask Netstar they say they don't have a record of my tracking unit being under my insurance whereas I pay Auto and General every month and i have an agreement with them. Can this please be rectified I cannot believe how this is not being managed in a proper manner that it should.