COMSAT is pretty big I think and I expect them to do better than this. Just so you know, take your case to the higher up who will care. If according to them is correct that all SE phone of that model have same problem you would expect Sony Ericsson to make a recall (or to fix for free) of that model but I don't see any Authorized Distributor doing it so they are lying.

Next time, just remember that every Tom, d*** and Harry can import phones, sell it as an AP set it via their own warranty but if your phone happens to be a lemon and needs some major repair than you are out of luck. As only AD can have spare parts, etc blah~ from SE. Most AP companies can only perform simple repairs.