Dear Sir or Madam,
I am writing to complain about a mobile phone handset, which I bought in your shop last month (exactly 20th January 2014). I had already phoned your helpline, but nothing has changed.
I am very disappointed, because I always buy products in recommended shops, but this time I made an exception and this was an error.
The faulty mobile phone handset do not work properly - the screen is blank. It seem the on/off button is jammed. When I was explaining this your helpline, they told me that this is my fault that the phone is out of order and did not explain how I can fix this problem.
In this situation I must ask for an exchange of a product. If it would not be possible, I want my money back.
I look forward to hearing from you.
Yours faithfully,
XYZ.