No guarantees with retentions plans once your term expires. Only way to try is to try. Depending on how far into your contract you are, you could just explain that you will sign for another 3 years if everything stays the same or you will be shopping both of your lines to other carriers.
Unlocked iPhone 5, unlocked iPhone 4
Unlimited airtime, Unlimited CAN/US long distance, Unlimited SMS to CAN/US wireless numbers
2500 Call Forwarding minutes to CAN/US numbers
Google Voice for visual voice mail with message transcription, conditional greetings, unlimited messages (vs 35 message cap), remote retrieval from any PC or phone, no auto-purge after 10 days and most importantly no $7-$8 charge.