SiriusXM radio on wanted renewal subscription, Internet

When I purchased my 2011 Ford a free six month subscription came with it.  Recently, all of a sudden, I started receiving calls all day long ever day for a few weeks.  Finally, someone told me what this was all about.  It seems they automatically renewed my subscription of Feb. 1, 2013 over a full year after I purchased the car.  All of a sudden I owed over a hundred dollars.  When I protested that I did not want the service the amount was "supposedly" reduced to 11 dollars.  When I protested that, the woman on the other end said she would clear the account.  

These people talk a certain script and never seem to deviate from it.  Their accents were so thick and they talked so fast, I couldn't understand anything they said.  The very next day they called again.  This time I was told that I would have to talk to the cancellation department.  I did and spoke with someone who spoke better English.  He took care of the problem, so he said.  The next day I received two more calls.  The first call, my husband spoke to the caller and told her that we had taken care of the problem and not to call anymore. She hung up on him.  We picked up the second call, only there was no one on the line.

These calls are coming from India, at all times of the day and night.  What kind of scam is this?! What kind of fraud, when some company automatically renews the service a year later and then wants payment for it?  I worry about my credit report.  This practice needs to be stopped.