Hey jkcert and djingga,
I am from Singapore.
I received similiar email reply from Sony Mobile Singapore regarding this issue as well.
They will refer you to go the service centre. If you read the terms or conditions of Sony Mobile Warranty, Sony will either repair the phone or replace the phone (could be a refurbished set with good working condition, not necessary a new one) at the service center's discretion.
It is Sony's company policy. So defective things has to go to the service center unless the store where you purchased your product from allows you to have an exchange of defective product within a limited period of time.
I understand the very bad experience. For myself, it was a nightmare! Like you, I said i would not trust Sony anymore. I signed up a new line for Xperia S and just after 3 days, the sign of flaw started to show on my phone. I contacted Sony and my defective phone was in service center. I request Sony to give a new handset replacement but they did not. My new phone was lying in service center for about 1 week. In the end, i thought it did not make sense to sign up for a new phone, but after a few days, i completely coulnd't use the phone, especially when the service center told me that there wasn't any spare parts for Xperia S yet and it might take at least 2 weeks or more to repair.
As i mentioned before, try to contact the store your purchased your phone from, or the mobile carrier or network service provider to see if they can give you a new replacement or do something about it.
Good Luck!
ps: The yellow tint is still an issue of the screen, depends on the severity.
