Hello @Gig18 , sorry you didn't quite understand the details of the offer. The device payment is charged separately from the plan. The device payment is charged the amount of the posted monthly payment and then the discount amount will show as a credit on your plan amount.
Also, if you are within the return period of your device, you may return it to Fido without penalty. If it was mailed to you, the window is 30 days. The device has to be in like new condition with all packaging and documentation included in like new condition. Check for a return envelope in your shipping box or call fido support for a return label as soon as you can to stay within the return period. Here are a few methods to get in touch with customer support. All the best