Returned Equipment But Got a Bill - DirecTV

Heres a quick run down of events:
1. Was a 6 year employee in GA. Left AT&T and moved to CT.
2. Cancelled my UVerse account, was told to bring all of my stuff to ANY UPS store.
3. Got to CT, got settled, went to a UPS Store. To my shock, UPS in CT doesnt accept AT&T Uverse returns.
4. Go home, call AT&T. Theyre confused. Call UPS. Theyre confused.
5. Call sporadically for a few months. Trying to return this box of equipment that is sitting in my car.
6. Finally in in September, get a hold of someone in AT&T to send me a UPS label.
7. Pay to pack the boxes up myself, bring to UPS. Attach the UPS label
8. Leave the equipment and box with UPS, assume all is done
9. Flash forward to January 2017.....I get a bill from a collection agency that the euipment was not recieved and i owe $675.

They want a tracking number. As if i kept that since September? Can someone please help me?

This question, "Returned Equipment But Got a Bill," is about DirecTV channels, programming, equipment, and sports.