iMessage Activation Error
I have recently switched phone plans to Freedom Mobile. I temporarily had a new number before my old number was transferred back. iMessage appears to be trying to use that number. When I go to Send & Receive in Settings, my email is there as well as my temporary number, but that number is grey and there is a loading wheel next to it. iMessage says it is waiting for activation and when I turn it off and on again it says there was an error trying to activate. I am also receiving texts from random numbers with coded messages starting with "REG-RESP?", I have looked up my account on the Freedom Mobile website and I have apparently send out texts to what appear to be UK numbers (I live in Toronto). I have looked it up online and apparently this is normal, but why won't iMessage work? I tried all the options that I could find online including restarting my phone, logging out and back in, as well as using Airplane mode. Is there a way to stop it trying to add my temporary number and add my normal one so that iMessage will work?
Thanks
iPhone 5c, iOS 10.2.1