Good guy T-Mobile

I bought a Sony XPeria Z phone while I was in the US, and was using it for few months, just 15 days before my international travel, I bought a new Nexus 4 and was using the phone to test it. Before traveling to India on or around Sep 13th (Note: I was using the phone till aug-31st), I called T-Mobile and requested a sim unlock code for my phone, CSR told it would be ready in 48 hrs, To my surprise, they rejected my request saying the phone has not been active on the network in last 7 days. Then I called up the support from India on or about Sept 20th and explained my situation again and submitted another request, at that time the CSR told me that he is raising a supervisor escalation and will be done. Again, it got rejected for the same reason. I called up the customer support again on or about September 29th, and requested to talk to supervisor, who assured me that this request is escalated to a different level and I will get the unlock code for sure. Attaching the "Wonderful" reply I got again , they rejected the request of course. As per your our support document, the requirement is to be active in the phone in last 40 days, it is sufficient. Then, why I am getting a run around ?

There are few questions I have about this:

1. When you are no longer selling the phones at discounted price, why are the devices still being sold as locked?
2. Why isn't a contact info on these "rejections", so that I can speak with the team responsible, directly.
3. Why isn't there requirement waiver for these nonsense rules, for international travelers ?
4. When a CSR Supervisor assures something and it doesn't happen, what should the customer do ?

Thank you for taking the time to contact T-Mobile. We have received your SIM Unlock Request. Unfortunately, this subscriber is not eligible to receive the unlock code at this time. In order to be eligible, the subscriber must have used the device within the last 7 days of the request being filed. Please submit a new request once this requirement is met.

I used a third party provider to get the unlock code and I had to spend $50 for that. 

General piece of advice : Don't buy phones from T-Mobile, directly buy from manufacturer. T-Mobile sucks this way.