The below letter is IELTS writing task 1. I am appearing for IELTS exam. I do not have any teacher to correct the below letter. That is the reason, i'm requesting your help to correct my mistakes. I would be grateful to you for your suggestions.
You have bought a mobile phone in a tax-free shop just a few days ago, and it doesn't work properly.
Task: write a letter to the manager to complain about it and ask him to solve the problem.
I am writing to express my dissatisfaction with a mobile phone that I purchased in your shop just a few days ago which was not functioning properly.
The first malfunction I noticed was mobile display which was not clear as much as when i purchased. I discovered another problem when tried to make a call, the network signal is not detected. When I compared with other mobile at the same location, which shows the signal in full strength. In addition to, sometimes the mobile is getting switched off automatically when i make a call. Moreover, the mobile battery needs to be charged everyday for minimal use also, but the manual says that requires charge two days once. I was surprised to discover that much problems in a quite expensive model.
I insist that you replace the not functioning mobile and send me a new one. Otherwise I will be forced to stop my payment to your shop. I believe this matter deserves your urgent attention.
I look forward to hearing from your as soon as possible.
Thank you very much Gil for your valuable suggestions.