provided by Star2Billing S.L.

It seems that current "Agent" module works a bit strange

My understanding of agent is :
1.Agent registers into system and get good prices form us
2.Agent gets customers and sets percentage of increase
3.Customer in his page see rates : Global Rate + Agents percent

So by this scheme agent actually resells traffic
What do we currently have :

Agent registers, sets percentage
During checkout System removes Agetns percent and puts in agents account

So actually customer perfectly see, which coission do agent has, which is very very very bad

I suggest to implement agent module in scheme above

You are confusing what an agent and a reseller might be!

Those are 2 different perspectives on a voip-billing application.
I will advice you keep the agent as it is and that you start to implement a new layer for reseller that will do
what you described this will cover different needs on the billing system.

cheers,
/Areski