英语写作作业

假如你是卜曼宜，你购买了一部某外国公司生产的手机，因有质量问题，要求该公司更换。请根据下列要点，用英文写一封电子邮件。
　　要点：
　　1问题：手机不响铃，不能发短信；
　　该产品已售完，无法更换；
型号新，无配件，无法维修。
　　2.要求：公司应尽快予以更换
　　注意：1 词数为80左右
　　2参考词汇：配件 ——spare part
　　3电子邮件的开头和结尾已为你写好（不计入你所写词数）；
　　Dear Sir,
　　I am writing to you for the mobile phone of Dephone-S250 I bought on 20th Apr.2008 at Tele Mall in Wuhan, P.R.China

Dear Sir,
　　I am writing to you for the mobile phone of Dephone-S250 I bought on 20th Apr.2008 at Tele Mall in Wuhan, P.R.China . I bought a mobile phone in your company, but it has some problems. The mobile phone cannot function of text,when had a letter to me that it didn't ring.This company require replacement after sales, mobile phone is not changed. Hope you will soon be replaced.