I am very good at praising organizations and people for things that they do well but I also believe that it is important to tell them when they come up short. There are several important things that you need to do, however, if you truly want to see change in a situation and not just vent your frustration:
1. Put your complaint in writing - I once heard a professional state that when a company receives a written letter of complaint they assume that there are at least five hundred others who are unhappy but didn't bother to write to them. Letters are taken seriously - even moreso than a telephone call or an email.
2. Address the letter properly - If you search for the name and address of the CEO or Manager you will know that the problem will be read, given attention and forwarded to the proper department for resolution. It is a totally different situation to have the President of the company give staff direction to resolve an issue than to merely tell a paid Customer Service Representative who might not even tell anyone that you called.
3. Tell the story with all the facts - Make sure that you include the dates, people involved and details of what happened so that anyone who is reading your letter will have a very clear idea about the problem.
4. Express your feelings but don't overdo it - It is fine to state that you are frustrated, disappointed or hurt but when you go on and on about how you have suffered, the problem can become secondary to your upset.
5. Suggest some options to rectify the situation - What you think might have helped may not be something that the company has even thought about and may actually become a solution that they value and can implement.
6. Request a reply - You are entitled to know that your letter was received and that efforts are being made by the company to make changes.
7. Provide detailed contact information - State whether you prefer an email, letter or telephone call and suggest the best times to reach you.
8. Put the letter in the drawer for a couple of days - Sometimes when you write a letter during a time that you are upset you have not said exactly what you wanted to say. It is therefore a good idea to put the letter away and bring it out when you have calmed down. You might even ask someone who you respect to read and critique it for you so you can do some editing before you mail it.
9. Read the letter out loud to yourself - It is amazing how hearing the letter is so much different than if you are reading it aloud. You will have a totally different perspective when you listen to your voice read the words.
10. Keep a copy of the letter - It is important that you have a copy so that you can either refer back to it or even send it to another department if that becomes necessary.
After you have completed the above steps, let it go! You have done your best and can not leave the problem in the hands of the company, If they resolve the issue you can celebrate and if they don't, then you probably will not want to deal with them again and within time you won't likely be surprised to see a downturn in their profits and customer base.
It is very important that you not let this situation have too much of your time and energy. There are other things that are more important for you to focus on instead.