Could 1 account call to many number concurrently ?

Dear Ribbit's Most Valued People : I am very interested with your service and API features, our team had been developing website with ribbit application for the VoIP feature, it works good and sound is nice, but we have big problem now. We are using 1 account ribbit to be used for calling many numbers concurrently. For example a client is calling a consultant using a ribbit account, but in the almost concurrent time other clients need to call their consultant using the same ribbit account, badly they can not make call because have to wait the first client complete the calling with consultant. We have used customer key or token from Add App in our account, our credit is available and plentiful. But the concurrent calling using an account is like impossible here. Our application is different than teleconference or customer service application, becasuse ribbit will call to client number and consultant number, and they do conversation by phone, this process will be happened to many clients and consultants in our website each hour or even every a 30 minutes. This application now is on hold and they are using TeleCam Web. Please help us how to make our application works, This is urgent. what you guys understand or get my application concept from my written ? If not, i will send the more detail to email. Best Regards, Reinhart