I know - I feel like I have interrupted them most of the time, I've had one instance where I call, they answered with ''Yeh??'' I was a bit thrown off - so I carried on being polite anyway and asked for the person I would like to talk to, and she responded with ''uufffffff'' and she huffed n puffed for a few moments, then hung up!!
Sometimes I prefer to get answered by an automated voice message!!!! lol
I try to stay super polite when they're rude - i feel like it annoys them more than if i were to be rude back! haha