1、第一部分：说明投诉问题
i must complain about …
i am not satisfied with …
i feel something should be done about
i am writing to inform （告知，代替tell） you that i find … unsatisfactory
i am writing to express / air dissatisfaction / disappointment / concern regarding …
2、第二部分：描述具体情况
the noise disturbs my sleep so that i can't concentrate during the work time , and as a result , i have made several mistakes these days .
for me this environment is very difficult to make studies and i need a quiet room .
3、第三部分：期待解决方案
i expect to hear from you soon .
please give this matter your immediate attention .
i would be very grateful （感激，代替thanks） if you could look into the matter as soon as possible .
and i am looking forward to an early reply .
it is high time you took some measures to solve …
i hope you will take steps to rectify （纠正、改善，代替improve） this situation soon .
i believe you will take my complaints seriously .
i would ask you to give back my money , or i would file my complaint （投诉） to the authorities concerned （相关部门） .
to solve this problem / surmount this difficulty / improve the situation / crack this hard nut （解决问题） , i hope to draw the attention of the authorities concerned .