where to start ?........lost paperwork.....lost mo...

where to start ?........lost paperwork.....lost money.......never returned legal documents........It's been a year since closing & now I find that 16K supposedly withheld for state witholding tax wasn't paid . Now I get to deal with state of Md., & all I get when I call Servicelink is a recording telling me they are to busy drinking coffee to answer the phone. What a bunch of "LOSERS"