As much as I like videotron services, they will probably want you to have a plan that has a minimum price to get a new device on a contract. Chances are its minimum 60 to 70 a month. The more you spend the bigger the rebate on the phone.
It's always possible to keep your rebated plan even when you switch phones. However, it's possible that if you want the latest devices at their full rebate a minimum monthly amount will be required like @Jeffg1 mentionned.
You can see all of our current mobile devices here.
In order to have the exact answer in regards to your account, I would suggest you contact us by phone or go to one of our stores: Contact us