callshop modules for a2billing !Urgent!

Hi we need a callshop module for a2billing. What we need to an addon for a2billing. We want to be able to offer our services to callshops. The callshop will get a callshop interface from us. They will manage their users and calls via their own interface. The addon will be a full callshop software, where the callshop owner can control all aspects of his shop. The software will be hosted on my site. The backend will be a2billing, where the callshop can top up there accounts. We need the software to be multi tenant, so we can offer this service to multiple call shops. thank you We have taken a look at this one, it has the concepts of what we need. [login to view URL]