Formal Letter to a manager

Dear Sir/Madam, I am writing you this letter to draw your attention to the faulty delivery made by your company. Last week, I purchased a desktop computer for my son from your online store, my request is consist of a main case of the hardware, monitor screen, keyboard and a mouse. Unfortunately, when I received the package and unpacked it, I got shocked from what I have seen, the monitor screen was scratched and the keyboard was broken from its left side, and in addition to that, the bottom cover of the mouse was broken. However, I immediately submitted a query on your company website, furthermore, I have been following up closely over the last few days and the only response I got is that they are working to solve this issue and will update me shortly, even though I sent a number of reminders on the query page, I still did not get any feedback! Thus, I decided to escalate my complaint by writing directly to you. Consequently, I would like you to replace my desktop computer with a new one if possible. If not, I request a refund. I am looking forward to your further action to solve this issue. Yours faithfully John Smith