In my young and foolish days, I actually accepted their Faustian bargain. When I fulfilled my end of the bargain (buying 6 full-priced CDs), they offered some absurdly cheap deal like "buy 15 selections from the full catalog for $50, no further obligation/strings attached" or something crazy like that, and there was enough stuff that I decided to take them up on it and ordered.
They sent me three copies of each of fifteen CDs. I called them up and asked what they wanted to do, and they insisted "no, we only sent you one of each, you must be drunk or retarded or something, we're good." So I took the duplicates to Best Buy to exchange them for store credit (this was before CH repackaged everything using private SKUs, so these all had bar codes and were all sold at regular stores), and wound up with about $300 in credit to piss away on something else stupid (I was young and foolish, so it was probably video games).
Then a couple months later I got a letter in the mail from CH demanding I either return the extra copies or reimburse them (at full retail, which they claimed was well over $500 somehow) if I'd already disposed of them. After chatting with a lawyer, I wrote CH back and told them they'd just committed mail fraud. I could prove I only ordered one copy of each album (I still had the packing slip from the shipment, which showed "Qty. 1" for each item, and for some bizarre reason (probably because I thought it was neat I could even do it) I'd actually scanned the original order form before I mailed it).
Turns out there used to be a common scam by fly-by-night catalog sales companies, where they'd mail you something (that you didn't order) and then demand later that you pay full price for it once enough time had elapsed that you were likely to have either put it to use or disposed of it in some way, in a strongly-worded letter implying you'd "stolen" the item or "defrauded" them somehow and they'd send the Pinkertons after you for it or some shit if you didn't pony up. The USPS considers that mail fraud. So I told CH if they insisted on pursuing the matter, my next letter would go to the local postmaster's office for investigation and I'd be sure to Cc the "account manager" who'd sent the letter.
A couple months after that, they sent another letter, curtly informing me that as a matter of "customer relations," they were closing my account (oh noes) and "electing" not to pursue collections, and considered the matter closed.