Unpaid for work done in Arizona

We are a small Mom & Pop trucking company. We had worked for this company called Alleco Stone LLC for a long time, they had always paid the invoiced amount and generally on time. Then mid summer 1998 they started paying slow, they told us they were having financial trouble,which we understood all businesses struggle at times. They asked us to work with them in their lean times promising to pay us in full when things got better. Well the pay finally stopped, leaving a balance of $23,223.75 not counting any late charges at all. They will not answer our phone calls, letters or faxes they have chosen to completely ignor us,, knowing full well they owe us these funds. Tom & Shiela Mattingley own the company, it's physically located at 10401 South Miller Road in Buckeye, Arizona. Their mailing address is P.O. Box 728 Buckeye, Arizona 85362 phone # 623-386-1148. This balance has been outstanding since Sept. thru Dec. 1998.For the year of 1998 we have the 1099 Form showing income of $48,697.00 before they stoped paying us. During this period of time we still had to pay truck payments, drivers wages, Insurance,fuel,repairs,tires,and on and on. Our phone # is 602-841-2701, address 9401 N. 36th Avenue Phoenix, Arizona 85051. John A. and Frances A. Briggs If there is anything you can do for us we would be so grateful as we are in dire straights. Thanks