Return device

Dear Xfinity Support,

I recently moved from Houston, TX, to Shrewsbury, MA. Since Xfinity does not provide service at my new address, I had to cancel my internet service. I also need to return the modem I received from Xfinity.

Today, I visited the Xfinity store in Leominster, MA, to return the modem, but they informed me that they could not accept it because I originally received the device in Texas. Could you please provide instructions on how to return the modem properly?