I had to call them over a routine matter (address change) a couple months ago and it wasn't so bad apart from the odd phone tree referenced in this post.

The waiting time was about what you mentioned, but there was a convenient option to leave a call back number so you don't have to wait on hold.

I made a total of 3 calls, each spaced a few days apart. The first two agents were markedly impatient and eager to get me off the phone for some reason. The third one was very friendly and helpful and finally resolved the issue.