This would be something best confirmed by contacting Telus directly.
If you cancelled last month then you would be getting your final invoice. Depending on the date your invoice printed and the date you requested cancellation, billing can get tricky. If you invoice printed on the 17th of every month and you called in to request cancellation on August 21, then your bill would have just printed. You would still have a bill owing and due around Sept 12. You would have one more final invoice print on Sept. 17 but, that would be $0 for the rate plan and only have any overage charges if you had gone over the usage of your normal monthly rate plan. Over your data or minutes. The bill on August 17 would have usage up until August 17. To confirm your services were cancelled, if you had an email on your Telus account, check your email. You'll have an email saying sorry to see you go with your cancellation date.