There are specific details one would need to know to arrive at the right accounting software. There are many variables which i can not say now because they might not apply to your situation. However based on the current geo location you are in you have various possible solutions according to your budget & platforms you are flexible with.
I strongly recommend PASTEL Evolution and you can contact Chips Computing or Pastel Zimbabwe for this.
However if you need a package that is implemented and in use successfully in the region then go for Microsoft Great Plains and Cogsdale implemented by PSU International.
PSU (Public Services and Utilities) International specializes in Revenue Management with a specific focus on Debtor Management based on data integrity etc see www.psu.co.bw