Will Xfinity bill me for UPS return?--RESOLVED

I'm trying to schedule a modem return to Xfinity via UPS. I have a return label that came with the new modem, however, when I enter the tracking number on the UPS website, it says that I may be billed for the pickup. I do not want to be billed for this pickup. How do I ensure that UPS doesn't try to bill me for an Xfinity return?

FOLLOW UP:  I called Xfinity support and they assured me that there would be no charge. I then called UPS and they also confirmed there would be no charge for the pickup, so I went ahead and scheduled the pickup. 

Thank you.