But it's NOT Matthews Pierce and Lloyd.  Someone posted that on this thread a long time ago and other people believed it and kept repeating it.  You are right though that it is a scam: the caller id is being spoofed and is not really a Local Office in Dallas.

Tell them to stop calling!

They keep calling they ask for some one that I don't know.
If anyone interested in starting legal action against this group let's start and have them shutdown.
What they are trying is to find someone that is old or doesn't understand and get personal info and credit card information this is a scam group

Never threaten a lawsuit you can not backup..You made be sued for such actions and have to pay for the other parties legal fees.

That might be good advice most of the time, but we're talking about a phone scammer here.  If they want to sue you they are going to have to admit that they were the ones on the other end of the line... using a spoofed number and making harassing hang-up calls to you and thousands of other people.  If this is really a debt collector they can most definitely be sued for these things and they will be the ones paying any legal fees.