Writing Feedback / IELTS; Write a complain letter to manager about mobile phone is not working [5]

Letter Requirements: Write a letter to manager to complain about you purchased a mobile phone from tax-free shop and it doesn't working properly. Ask him to solve the problem.

Dear Manager,

I am writing to express my feeling about the Mobile Phone that I bought from your tax-free shop, few days ago. After few times problems started to appear.

The malfunction I noticed about hanging the mobile phone when I tried to make a call. I am very surprised to see that much problem in a quite expensive model. Naturally, I returned the mobile phone to your store to be replaced with the new one. Your assistant said that it will take time. After four weeks later, I contacted by your store representative and I learned from him that I can't receive new mobile phone for the one that I bought.

I am very disappointed with the product and services that I received from your store and expect from you to serious action against my complaint as soon as possible. Otherwise I will be forced to stop the payment to your store.

I look forward to hearing from you.

Yours sincerely,
Mr. John