Three's Not A Charm.
I noted a tweet in which the author complained that he'd be on hold with a customer service phone-line for so long that he'd realised that the music being played to him was a loop of three tunes and he'd hung up.
Now, obviously, he'd been kept holding for far too long. But it's also true that the company in question had idiotically ensured that he realised this by limiting the music to a cycle of three. The first priority is to deal with the customer swiftly, the second is to ensure they don't feel taken for granted.
In this case, the company got it wrong on both counts. If I were him, I'd ring up and complain. Or maybe not.