Dear sir or madam,
Thank you for in advance for your attention to this letter and I\'m writing to present my complaint /inquiry /application/apology/concerning sth that.....(concerning computer that I’ve brought in your shop last weekend)
(1) There are en array of factors contributing to (result in) this,(a)
initially ,in the second place......,additionally......(b)两点时For one thing ......,for another......
(2)There are hosts of aspect I\'ll offer have....
I\'d be most grateful if you can reply me at your earliest convenience and any favorable considerations will be greatly appreciated. Yours sincerely