I have the same problem with NFS Most Wanted:
A server error has occurred. Please visit www.eamobile.com/countrygate to chose your country and click the customer support link. (5003)
I have tried everything suggested (+ anything I could think of) to fix the problem without any success.
I have several questions for EA:
Q1.: What does this error mean?
Q2.: Are your servers offline/overloaded (probably not, since this issue exists for a long time)? Its not a connection problem (I am using my WIFI with rly stable cable connection to a good provider).
Q3.: Is it a compatibility issue? Could I fix it somehow (rooting device and changing settings / software)?
Q4.: Are you working on solving the issue? It exists for a seriously long time ... so what is your progress?
Q5.: If I have purchased any app with this problem how do I get a refund?