Return Label for Old Phone

I ordered a new phone by Internet.  There is a new process now where someone comes up to your home to set up the new phone and they did not provide a return label.  The phone was not sent out as a marketing package with a return label for the old phone.  I tried to get a return label for my old phone at an authorized ATT store and they said they could not provide a return label.  I called customer service and they also said they could not provide a return label.  This has created a lot of back and forth on the phone with ATT representatives without resolution.  This has been very upsetting and time consuming on something that seems very simple.