Best Buy customer service fail

Like many IT pros I end up doing a certain amount of PC support for the extended family. My mother in law lives 100 miles away so supporting her is usually over the phone or when I can get by her house. Recently she bought a netbook from BestBuy. This was before Microsoft had released Windows 7. When she bought it they told her it came with a free upgrade to Windows 7. Well Windows 7 has been released and she went after her upgrade. She asked the BestBuy Geek squad about it and the said that it was ummm... not actually 'free'. It would cost $40 for them to install it on her netbook. OK....(Crickets chirping) Well I understand the whole 'I need to get paid for work' but the upgrade was 'Free' right? Free is free right? Wrong. So she gives in and says oh well go ahead and do it. Then the Geek Squad guy comes back and says that the Antivirus package that she uses is not compatible with Windows 7. He offers to install Norton or McAfee. At a cost of $30. What a load of BS. How does a 'free' upgrade lead to $70 in charges? Why does Best Buy think they can take advantage of my Mother in law?

*** Update***
I sent this link to the store manager and he immediately got back to me. He informed me that there had been another option which had not been presented to my Mother in Law.  This option was to get the free copy and load it herself.  Since I support her PC this is the one I would have directed her to.  He asked if he could talk to her about the situation.  At the time I had directed her to go ahead and get it loaded but I had not thought she would have done it so quickly.  So net effect is that they did load it and she was charged the $40.  I just wish she had been presented with the other option.  To his credit the manager tried to make it right but the timing just wasn't there.  They did do the work so they do deserve the money for loading it.