MacKeeper is definitely not a "virus," or any other kind of malware. To say that it is is extremely misleading, and causes much confusion as to what is or is not malware. It is what many here would call "crapware." It is extremely aggressively marketed, in sometimes very unethical ways, and once on your machine, it scares you into buying it to fix thousands of "critical" issues that are actually not problems at all. It is "Apple approved" in the sense that it is signed with a developer certificate issued to Zeobit by Apple, and there is a trimmed-down version (called "911 Bundle") that has been approved for the Mac App Store. None of this means that Apple actually recommends installing it.
People who have requested a refund from Zeobit have actually been successful, so it would not be a waste of your time to try to get a refund.