Need help to network unlock my HTC ONE M8 on 4.4.2

[miamicuse]

Hi, I just bought a new AT&T HTC ONE M8, have been using a Samsung Galaxy S2 on T-Mobile for years.

When I inserted my T-Mobile SIM into the phone, it says Network Lock Enter PIN. Ok no problem I just need to buy a network unlock code from somewhere on eBay.

However I went to two different merchants on eBay for the unlock code and I see in their descriptions that if my HTC ONE M8 has Android 4.4.2 on it the unlock code would NOT work. I just checked the software version and it is indeed 4.4.2. So there is no easy way to unlock the phone? :'(

 

[miamicuse]

Got two vendors who sells unlock code said Android 4.4.2 is bad news and the unlock code will work if I downgrade or upgrade to another Android version even 4.4.1 or 4.4.3.

How would I do that when this is a brand new AT&T phone network locked, and I need to put it on T-Mobile? I can't get the push from the network to upgrade or downgrade.

 

[wow08816]

You can manually flash your ROM. See HTC manual system update information at near bottom third of page http://www.htc.com/us/support/htc-one-m8-att/news/

 

[saltire]

Isn't it easier just to contact AT&T to get unlock code?