guys , need your help , is there any chance or quick soulution to take care of this problem :

1. the att blackberry onyx 9700 device is using tmobile provider and can't use push email and network only "EDGE"

2. and i want to use this push email even if i'm using this the same att device and still using tmobile network , i don't want to change to att provider , is that possible ? please need your help . thx