Camera Return

I am so done with Xfinity, I bought a few cameras with my WiFi and cell service as they convinced me I needed them. 3 months later they were never opened as I never got around to it and never needed them, I have since cancelled my service and moved, and now I cannot return them, I have the receipt and the boxes seal isn’t even broken. I owe $250 on cameras I am not using and I refuse to pay that. I cancelled all service and now have overdue balance on those cameras and I am not paying for it. Is there any way I can return these even though it’s past the date?? This rule is an absolute joke, please help!!