I should like to complain about the dropping standards of complaining, that's my main complaint.
Years ago, when I worked in a customer services role for a major UK telecoms provider, we received good complaint letters. Some of them were so good, they were photocopied and pinned on the staff restaurant noticeboard.
Nowadays, people don't take the time to complain in writing, standards have fallen drastically and lazily, customers will now merely ring a call centre and become annoyed at whoever is unfortunate enough to take their call. Alternatively, web-based complaint/contact forms are filled-in, but these are mere shadows of the excellent complaint letters of the past.
I should very much like if we could start taking the time to write proper complaint letters again because it must be very boring for those who work in customer service roles nowadays. Even face-to-face, customers can no longer complain creatively and they back down far too quickly.
I have fond memories of a customer becoming so upset, they pulled out an 18th century sword in the reception area of the building I worked in - now that's proper "don't mess with me" complaining. I also remember, after a long running dispute, a customer finally agreed to call, in person, to pay their bill in cash. It took over half an hour for several security guards to unload almost £5000 in bags of 1p coins from a van.
Let's remember a time of greater complaint effort and try to raise the standard for all. In the meantime, I would suggest not taking an 18th century sword to any company's reception area, amusing as the staff may find it for years thereafter.