We also did work for M&M and were never completely paid.  They sent us several months of postdated checks and the first check we had no problem with.  The next check we had was returned for non-sufficient funds and after that, I would call the bank to see if the funds were available and they never were.  I tried to contact M&M but was unsuccessful and i then wrote off the remainder of the money owed.  M&M  are liars in my opinion.