Onstar Subscriber Services

I cancelled my vehicle wifi service through OnStar and was told my service would continue another weeks as I was paid up through thenImmediately after, my service stopped workingI called in two days later and asked that they turn the service back on, so they created a ticket to look into the problemIt has now been a week since creating the ticket, so I called back in having not heard anything back from themThey transferred me times then told me there is nothing they can or will do for meThey've accepted my money yet are refusing to provide the service I payed for or a refundI know we're only talking about $20, but it's the principle of it