Worst Business Correspondence I've Ever Seen

I just got this letter in the mail today.  We had this company aerate our lawns one time, then they came back a second time though we didn't authorize them.  I tried calling to tell them that we no longer wanted their service but they never answered the phone.  Finally, they were at a neighbors house, so I was able to tell them.

Here are a couple tips when sending business correspondence:

1. Make it very clear what action you expect from the recipient.
2. Be concise.  Don't repeat yourself.
3. Check spelling and grammar

Do you have any additional tips for how to write business correspondence?

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