I sit with the same problem. Invoice is R18K, client short paid by R6K since they feel that a lot of the work was over-invoiced for. Part of the R18K invoice included MS Office, Quickbooks & Antivirus licenses so the R6K was pure labor. We spend a whole week at their premisis doing a lot of work (migrating data from old PC's to new PC's, cleaning out virusses, upgrading MS Office, diagnosing & fixing compatibility issues with Quickbooks 2002 & Windows 7). We're still trying to get the money from them since October last year.