So the good news is koodo doesn't do the contract thing. Log into self serve and check out your tab balance. That's the amount you need to pay to get a new phone maybe. It depends on what phone you can want and how much tab u have. Now more good news, you can click to have that billed to your next bill and while you're in self serve, order a new phone using your now clear tab.
You can check your remaining tab in selfserve and pay it off right away if you want to use the tab again if that's what you meant by finishing your plan, but it might be wiser to get another phone that is second hand or a moto g until your tab is finished off depending on the situation.