Welcome to the community!
If you would like to keep your old phone number, you would need to contact customer service to request the number get ported from Rogers. It would be important that you do not cancel your services with Rogers or else they won't be able to port the phone number. Once the port is completed, your Rogers account will automatically be cancelled.
Alternatively, you might consider sending @FidoSolutions a PM. Once they verify some information, they'll also be able to access your account and initiate the port request.
Unfortunately, if the line with the other provider has already been cancelled, it's unlikely you will be able to get the same phone number. Generally, once a phone line gets cancelled, its associated phone number is out-of-circulation for a period of time. Other providers won't be able to access that phone number.
I'm not positive, but there may be a way for the original provider to possibly reverse the cancellation?? You might consider contacting your original provider to enquire if such a procedure is possible.
Hope this helps 😀