[Skunkworks] Setting Up Tariffs on Mkahawa

Dear Friends, I am currently installing Mkahawa in one of my cybers. I have installed the clients and the server and they can communicate properly. Now, I am stuck on the tariff part... I want to charge the kawaida 50cts per minute with a Ksh. 10 minimum... I have tried all manner of combinations on the tariffs setup tab, but I simply cannot figure out how to setup the abovementioned rates. The billing is going haywire and sometimes it charges more and sometimes less... I have attached a screenshot herewith of the place I should enter the figures. If there is a Skunk/Skunkette/skunkling herein who has setup Mkahawa, please please please guide me on how to setup the tariff...please...tafadhali... Timo.