Apple customers, meanwhile, continued to flame Apple on Twitter, or in some cases, surrendered.

"24 hours later and still no redemption code for Mountain Lion from Apple. No communication, nothing, zilch. Great user experience, Apple!" said on the micro-blogging service.

"Finally caved and purchased #MountainLion. Will chase for refund when I finally get redemption codes. Fairly disappointed," concluded .

Apple did not reply to a request for comment on the Up-To-Date code complaints.

Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld. Follow Gregg on Twitter at , on or subscribe to . His email address is .