It's not a matter of *****ing, When I taught a business writing class, I included information on how to complain effectively. Here it is, free:
1. State in the first sentence why you're writing. "On Friday, May 11, X happened. As a result, XX and XXX happened." Give enough details that they can get the complete picture without having to refer back to anything else, although they will have your information on their screen.
2. Tell 'em what you've done since then. Be specific and list every contact, with whom and what was said. "Since then, I have taken the following actions to resolve the issue:..."
3. Tell them what their representative said. "Your representative told me that X would happen by (date.)"
4. Tell them what hasn't happened. "However, since that time, I have not heard from anyone..." or whatever.
5. TELL THAM WHAT YOU WANT AND THE EXACT DATE BY WHICH YOU WANT IT. Make it reasonable. If you demand action within the hour, you are probably wasting your time. But if you say, "I expect to hear back from your Regional Manager no later than 5:00 om on Thursday, July 13" they will know exactly what you want and by when.
6. Tell them what will happen if your demand from item 5 isn't met. "If this matter is not resolved to my satisfaction by that time, I will write to..."
Delete adjectives from your vocabulary when you write. Be polite, firm, and 100% factual. And of course, in order to do this satisfactorily, you need to keep complete notes on every effort you've made to resolve the issue.
If you are polite, firm, factual, and unemotional, there's no way they can dodge you. Almost every one of my students reported positive results when they stopped yelling, using adjectives, and letting them get away with empty promises.
One more thing - don't call them - there's no trail from a phone call. Do everything by e-mail.