Who called from 9523505998

Caller keeps calling and not leaving a message. I don't answer number I don't know.

They left me a brief message. Something along the lines of thank you for your time, if you have any questions about this call from Xfinity call 1-800 something, then something about Comcast in my area.

Called and left no message

I got a call on my cell phone from this number. I answered it and said "Hello", but it was dead air on the other end. I tried one more "Hello", and then hung up.

Follow-up. I just got a call from this number a second time. They claimed to be from Comcast. I hung up on them.