iPhone to iPhone can't receive texts...

This just started happening, I keep trying to text a friend who has iMessage turned on but I do not, and I don't keep my data on because I am on pay and talk, not a monthly bill, so I only use it for recieving pictures through messages, or going online when I'm away from wifi....

When I text her, She receives it and can answer back, but for her all the texts are iMessage even though I have mine off. Through my view, all the texts are regular text messages. We both have MMS texts turned on, and have the same model phones (4S).

She called both our service provider(Telus) and Apple, and they both told her it's my phone, and that I have to disassociate my Apple ID and my phone number, which I have done, and it still isn't working, she has to change certain settings for me to see her reply. Otherwise it's as if she doesn't text me back.

Any help would be greatly appreciated.