Well I bought a laptop from them and it came with 1-year insurance, and after 6 months, the hard drive just stopped working. I went in, they said "no, we can't help you unless you bought a geek squad extended warranty" blah blah blah all this crap. After three months of fighting Best Buy my dad finally got them to fix it.
Just recently, I lost my wallet with a Best Buy store credit and when I called them, they said "take the receipt to the store where you got it, and they can replace it" and when I went in, they told me they don't have records of store credits because they are just like cash. I was like wtf?? Seriously, if there's no record, how can they be spent. By the time I finally got Best Buy to fix the problem, it had been spent and they wouldn't replace the lost value.
My sister's boyfriend bought her this built in ipod thingy for her car and it came with free installation. After they bought it, the guy was like "oh no, we can't install this because you didn't buy it from the audio section" so they returned it, went back to the audio section, bought it for the exact same price, and got it installed.
Best Buy just has serious customer service problems....