I am so sorry to hear about this. Although I cannot confirm what email you received, I assume it was not a genuine TELUS email. I too have received these emails and they look very close to real emails from TELUS.
First please call Telus Mobility at 1-866-558-2273 as soon as possible and confirm if your order is genuine. Let the agent know you responded to an email to get a free iPhone, just pay $3 shipping, and are concerned its a scam. The agent will ask you some questions to see if they can find your order in the system. If no order is found, and no record of any communication, I would strongly advise you contact your credit card company and let them know you were a victim of fraud. Provide them with the date you provided the credit card information, and they will investigate and likely cancel your credit card as an extra precaution in case its compromised.
If you know 100% it was not a genuine TELUS order, you can also contact Equfax 1-800-465-7166 to put a fraud alert on your credit to ensure no further damage can be done. Click Here to learn more.