I get calls from this number everyday. Leaves no message. How can I get them to stop.

i recieved a call from this phone number yesterday when the woman spoke i couldnt understand her so i told her this and asked to be put on the do not call list. that was all great until i recieved another call from them a few mins ago what can i do?

I have been getting this call for over a month now.  
We don't answer & they hang up before the vm kicks
in.  I have tried to call back (801-229-2252) but
always get a busy signal

Je suis écoeuré de recevoir des criss d'appels de ce numéro bizarre!

I've been getting atleast one call a day sometimes 2 calls a day from this number on my cell for the last few weeks.  Its usually when my cell is not on me.  
Today I finally was able to answer my phone and I could not understand a word this lady said other than my name.  
I see someone here just said its a circut city #. Just recently I sent an old circut city gift card to Utah to be reimbursed the $ on it since we no longer have stores here.  I wonder if it has something to do w/ that.