Netstar online presence sucks

I have been a member of Netstar and have been paying since 2002. i have sold me car recently and I tried to find a contact number and searched online, but the research came back that i am not a client. this was done this year Your Netstar unit is now active: ***5-CA846020 :HATCHBACK

I would like to get hold of Netstar to change to my new car. I am currently paying for a unit in a car that was sold 2 months ago.

Please help Martie