How to reply to a stong complaint?

[antokiswanto]

I have been working for a company and I sometimes receive complaint letters. Sometimes, when they complain so strongly, I am not interested in solving the problem and ignore them because I cannot make a long explanation. Shall the letter be long or wordy?
I have just found an article but my question is : Are the phrases gramatically correct?

[Anglika]

Welcome to the forums.

I have been working for a company and I sometimes receive complaint letters. Sometimes, when they complain so strongly, I am not interested in solving the problem and ignore them because I cannot make a long explanation. Shall the letter be long or wordy?
I have just found an article but my question is : Are the phrases gramatically correct?

What phrases?

If you want to check your own letters with us, please post them for comment.