virgin mobile/broadband said I did not mail vack usb device and won't refund my money. always starting an investigation, Internet

They sent me a new usb device for my laptop. I sent the old one back in their pre-addressed prepostaged envelope immediately, within minutes. They shut off my service and when I called I was told they had started an investigation on the issue and I would hear back within 72 hours. This has been going on for weeks. On the 26th of Jan. of 2012, I was lied to and told my $53.00 and some change was credited back to my credit card.

After checking with my bank and calling VM back several times, today they admitted they were going to hold my money until they get the device back but would gladly start another investigation. As far as I'm concerned they are a bunch of liars and ripoffs. If I had the money to sue them I would. They basically called me a liar and said I didn't send a broken usb device back, like I would have a use for it. I'm hoping I can find someone else suing and I can join in.