Sony Ericsson — Manufacturer Fault

My Telephone was purchased on 20th April 2010, Vivaz Silver S/N [protected] company invoice no. 0658 (copy attached) On 3rd of July the phone was dropped at the maintenance section of the company due to a problem with the charger (following charging the Unit, I proceeded to remove the charging plug from the Mobile in which the whole socket came out with the plug). Receipt no. 0139 (copy attached) When taken to the mentioned section there was an argument concerning the problem and how it happened.
The phone was only two months old and this problem can not happen to a well made Mobile.
We finally resolve the issue with a 30 USD payment to fix the problem, even though I still think that warranty should cover this yet capitulated to what the agent demanded since I realized that they are just not concerned about my plights.
In a week time when the parts arrived. I was told that the screen of the mobile was not working; I replied that I have brought the phone for the charger socket only. Why I was not told that there was a fault with the screen before hand? I had no problems with the screen before hand.
I mentioned again that the phone was still under warranty and they have replied that the warranty does not cover such faults.
Up to this point I was given promises that the phone will be fixed. Not replaced.
I am shocked that a reputable company such as Sony Ericsson is not being able to satisfy its customers; personally I would call that agent in Yemen and rate his service as in unsatisfactory customer service and a RIP OFF.
Grateful if you could look at this matter, Sony Ericsson will not lose their reputation for such an agent.
On 19 August I went to Sony Ericsson to check on the progress on my phone, I was told it was ready to be picked up with a payment of $100 up front.
Now when was It a common practice to get things fixed prior to customer approval, I should have been told before hand what the problem was with the phone and whether or not the warranty should cover the cost. Also, who authorized the dealer to change parts without my approval?
How cans the dealer, tell me that they have changed parts and give me a price after the fact. This is bad business and gives Sony Ericsson (a reputable company) a bad name. Thanks.