i own a cleaning company in mo.i am owed $2.200 from property management.i had told them no more work till im paid.What can i do.?

they said i did breach of contract,contract never signed by either party.aslo try and said i did a bait and switch due to x charges on original bids. although they knew there would be x charges on over used chemicals.i also had to clean in no ac me and my workers i never complained and also they said in my contract i was to bill them every 30 days then they had 30 days to pay which once again never signed on either party and all in all half of them are over due past the 30days,anyway.so now i have asked repeatly for my money in e-mail and texting. and im getting no where.so i had my workers call them and say they need to be paid (which i did pay them) but i was to see if they would respond and they did by saying it was harassment and to get the money from me .