Originally Posted by
gemac
I can understand why you find AA's 1500 character limit restrictive.

I do not mean to bash the OP with my comments below and I do hope that they find a resolution to their claims.
A proper complaint letter, IMO should be clear, concise, to the point, and unemotional. The response you got was boilerplate because, I'm assuming, your initial letter was long. The agent (who I'm assuming has targets to meet), scanned the e-mail for key words to the complaint without fully reading it and decided this was the best template for your answer.
Without knowing what exactly you wrote, based on what you describe below my letter for your complaint probably would have looked like this:
Dear Sir, Madam,
Reference: [quote PNR or Ticket no]
Due to an operational delay and a series of errors involving passengers having to be offloaded to accommodate maintenance crews positioning to CUN on flight [flight no] on [date], the arrival to our final destination was delayed by over 24 hours. Please refer to the reference number quoted above to see our itinerary.
Because of this delay, I have suffered a financial loss of [amount] as a result of having to buy supplies for the forced overnight stay at MIA where our bags couldn't be retrieved and [amount] for one lost night of our pre-paid hotel accommodation at our final destination; totalling [amount].
As this delay was not due to extenuating circumstances I trust that I will be compensated fully for my losses.
Sincerely,
You're after compensation for your losses and that should be the main point of your letter to them. The above is under 750 chars, not even half of the limit.
The airline's responsibility (and your contract with them) is transport from A to B. Compensation for your lost hotel night at your destination doesn't fall within AA's responsibilities and a good
travel insurance with
trip-interruption coverage is your best answer to reclaim losses. I would suggest checking with your credit-card company to see if they offer this service.
I also wouldn't hammer on safety because bags travel on different flights than their passengers quite frequently, although this was an error on the part of AA.