I get calls from this number all of the time and I have called TXU and they are unable to remove my number because the "account" in which this number is attached to is still active. I have had this number for two years and still get theses calls.
Today, I went on the TXU website and sent an email via this form via this link https://www.txu.com/contact/email-form.aspx
You do not have to put an account number or name. Hope it works!
TXU is an energy provider in Texas. This number is a courtesy call to let you know your bill is past due. If you are getting a call from this number it is because either your energy bill is past due or a person who has had your number before had their account tied to this number. There is an opt out and you can call TXU and have your number removed. This is not a scammer it is a totally legit call and is neither the fault of the phone provider or TXU. I am the first one to jump on the DNC list trust me but this is not one that qualifies.