The Nokia Lumia 900 for AT&T unfortunately faced connectivity issues on select devices for certain users. The company didn't take long to respond to the issue and have stated that a software update will be released on Monday, April 16 to fix the issue.Users who are facing this issue can wait for the software update or head back to AT&T and walk away with a new unit on which the issue has been fixed.
Nokia is even crediting $100 to the AT&T bills of everyone who has purchased or is planning to purchase a Nokia Lumia 900 on or before April 21.
The Nokia Lumia 900 is available on AT&T for $100 with a two year contract, so if you decide to purchase a device between now and April 21st you will basically be getting a premium Nokia handset for free because of the $100 credit.
source - Nokia