I'm not a complainer by nature, but I'm also pretty insistent about principle when I feel any customer service business has done wrong by me.

But I have *never* seen an instance where heated language or personal attacks have helped me get a problem resolved. They only make the agent you're working with less likely to help you -- and more likely to do what they can to shoot you in the foot. This doesn't mean you can't be frustrated -- but try to be frustrated at the problem, not the agent.

The CP agent or baggage clerk or gate agent didn't MX your plane or reroute your bag to Alberta. And US in particular seems to put a lot of roadblocks in the way of its customer service personnel at times, sometimes for valid reasons (preventing customer abuse of lenient policies), sometimes not (penny-wise, pound-foolish revenue protection). However, I find that customer service problems you're discussing with an airline staffer usually fall into one of several categories; realizing which you're in and responding correctly can really speed you along:

1) The agent knows how to fix your problem, and does. Obviously, this is the ideal condition.

2) The agent doesn't understand your problem. In this case, best to just hang up and call back -- it's hard to get an agent to escalate something they don't understand, since it makes them look bad. The next agent will probably know more.

3)The agent understands your problem, but doesn't know how to fix it. This is where it's easiest to get escalated to a supervisor -- since the agent will generally advocate for you with whomever has the knowledge necessary to solve the problem.

4)The agent understands your problem, but isn't allowed to fix it. These are the calls that involve phrases like "I'm sorry, but the system won't allow me to..." or "We used to be able to override that..." Sometimes, you can convince the agent to break the rules, but sometimes they're really locked out. In these cases, I've found the magic phrase is "Can you help me figure out who I need to talk to to solve this?" The CP line can't find your bag, but they can sometimes get through to the baggage office that isn't picking up their phone. Except in Boston.

5)The agent refuses to solve your problem. This is the stickiest situation, and thankfully the rarest. Obviously, if you are asking for an exception to a policy and know it, be polite, appreciative, and get off the call as soon as possible so you can call back and ask again

But if you're sure you're in the right, staying calm and focused on the issue is key. The worst thing you can do in this situation is make it personal. The agent is doing what they think their job requires of them; in many cases, they think they'll get in trouble if they don't say no. The converse of that, though, is that if they're sure they're right, they should be willing to let their supervisor affirm their position. I will generally tell the agent that I appreciate their effort and assistance, but that I cannot accept their answer, and will need to talk to someone else about it.