Welcome to the community!
From what you note, it sounds like you might have a subsidised plan. For a while, any mobile providers used a subsidised model for their contract devices. This model is different from a tab or financed model or the more recently available leasing model (ie Upfront Edge etc).
With the subsidised plan model, the cost of devices was incorporated into the cost of plans (ie Small, Medium, Large, etc). As mentioned below, you should note that Fido has recently switched from their old subsidy model to a financed Payment Program. With the new model, the cost of devices is separate from the cost of plans. Since the costs are separate, you would no longer have a monthly finance charge once you have paid-off the balance of the phone. Is it possible you have a subsidised plan?
While there may have been some overlap between the two programs, it sounds like your plan was subsidised. If your plan is a subsidised plan, your monthly billing would not automatically be reduced once you have paid the balance of the phone (see here). It is not possible to simply remove the subsidy from those older plans so you would have needed to have switched to a BYOP plan -- one without subsidy. However, you should note that the details of the new plans may not be the same as your current plan. If you did not switch plans, you would not automatically get a new cellphone. In order to finance another device, you would also need to switch to a new plan as the old subsidised plans are not compatible with the new financed model.
You should note that this forum is community-driven and not intended as a venue for customer services. If you would like to discuss your plan, you would need to contact customer service. In addition, they can also be contacted via Live Chat, Facebook, or Twitter. Those methods can be accessed via the contact page posted above.
Hope this helps 😀
Hey @hgmiel! If you financed your phone with our Fido Payment Program, after 24 months, your device is paid off in full. At month 25 you no longer have a monthly Fido Payment Program charge, and you only have to pay for your regular monthly phone plan, plus any other services you have. Please note that as long as your line is active, you will be charged your monthly service fee regardless of usage or not. If you'd like us to go over your bill with you, feel free to contact us and we'll be happy to help.