Miller & Levine, Inc. I think I will need a new collection agency to collect from my collection agency!! Internet

I am a construction company owner.  A GC owed me almost $4000.  So, I get a call from Miller & Levine, Inc.  They talked a good game!  After about 3 months they managed to collect a mere $1500 of the debt.  Worn out from it all, I agreed to take it.  THEY COLLECTED THE DEBT ON FEBRAURY 17th!  Yes, here it is...June 14th...and still every week for months now it comes out of my pending file that I must call them yet again because the check that they promised me still has NOT come!  Oh, and by-the-way, don't bother to try to call them after 3pm as it is way too late to have to pull your file and get a call back the same day!?!?  Seriously...3pm?  Very unprofessional company to deal with...VERY aggravating!  Constant follow up on YOUR part!