You need to read their small print. They understandably say that it’s for retail use, not for business, and that the service cannot be resold.
We have several customers who left us for such services and have come back again. Their accounts become blocked when they start sending large traffic volumes.
Basically, you have to understand that you cannot get something for nothing. Companies offering ‘unlimited’ are in business to make money, just like you are. They are not going to let you send thousands of minutes a day for a dollar or two!
So they will not provide a reliable solution for your call shop.
– A reliable VoIP service but without unlimited plans 😉