I bought a new phone and plan from Sprint and was ...

I bought a new phone and plan from Sprint and was getting a $50 rebate as part of the deal. Mailed off the proper information and documents off to Mobi Wireless Management. When the check for the rebate finally hit my mailbox, they got my last name wrong. Been trying to contact Mobi Wireless through their marketing department about the discrepancy, but all I get is their voicemail. I've left several messages, but no one even tries to contact me back. Even emails don't get responded to.

Needless to say, their customer service is SEVERELY lacking.