Phone trade in issue

I upgraded 2 phones, according to the email I received I could return the phones to a local store or ship them. I took them to the store and they told me they can’t accept them and I had to ship them. Ok, so now I package them up and take them to the post office and the supplied QR codes don’t work so they can’t take them. 

I use Xfinity app live agent chat to find a solution, he tells me I have no phones to return and he can’t do anything 

I have wasted much time and gas driving to an Xfinity store, getting phones packaged for shipping, going to post office, then an hour online chatting all to resolve nothing. I keep getting emails to send in my trade ins yet you keep stopping me from doing it every way possible. I have reached the point that I want to take all my phones and cable boxes back to the store and cancel all services, as there are multiple options in my city now for high speed internet, phones, mobile and tv service