Zoom Phone Not Working

I purchased the $10/mo Zoom Phone plan and no matter what I do, I cannot get it to work. I have a digital number but it does not allow me to make or receive calls and it is very frustrating that no one will talk to you, especially when it's holding up my business. Can anyone provide guidance?  When I try to call, it just says: "Sorry the requested service is not available in your calling plan" but I'm positive that this is what I signed up for. Please help!!!