I hear ya - do the right thing - though what p*sses me off when I've faced similar situations in the past is that it generates work for me to fix their mistake. Either I find an email address to contact them, or call them on the phone, then there's the back & forth explaining the issue, then it's scheduling a time for a UPS pickup (or driving to UPS), then awaiting the receipt of the new cable. I recently had a situation where Zappos sent me shoes I didn't order. I called them a few times about it, and they would only accept a return if I scheduled a pickup from UPS. They wouldn't send me a UPS label to drop the shoes off at UPS (requiring my own time & gas). So instead, I would need to take a day off work to arrange a UPS pickup to fix their mistake - or I could just keep the shoes as they offered. I think y'all can guess the obvious decision. BTW, I did send Sennheiser an email; let's see what they what to do.