need some help with data

So i recently upgraded my plan so that i could have data on my iphone 3gs. But for some reason it keeps saying that im unsubscribed to a data network. I called rogers and we went thru a list of things of which nothing seemed to work except one, which was to completely restore my phone to factory setting and delete evrything. when i did this my data worked on the phone but the problem is i when i try to restore my phone from backup after so that i can get all my stuff and conversations back its stops working again.

is there any way i can have all my stuff and the data to work/ does anyone know why my backup wont let me use data?