Add to you Block list. It's Southwest Credit Systems (debt collectors)

yes, the block list is an appropriate resource to be used for the guys from Southwest Credit Systems, and any other collection agency using nasty tactics trying to collect debt well beyond the legal staturial limits of most, if not every state.  

the only problem I see here is that one needs to block too many numbers, as Southwest Credit Systems uses many different numbers, and not just 312-756-0790.

Constant calls then hang up......

Southwest Credit Systems is using 312-756-0790. This is a collection agency using nasty tactics trying to collect debt well beyond the legal staturial limitations of most, if not every state.  

Don't fall into the trap of talking to them. They will try to intimidate you with empty threats.