Phone Service Help

[Austin Faux]

So I still work my 9-5 and can't always get to the phone.  I currently use Switch.co for my business number and I have a answering service at a different number.  I'm trying to figure out if there is a way that if someone calls my business number and I can't answer by the 3rd ring, it automatically sends it to my answering service.  

My answering service says it would have to be through Switch.co that it would work, but I can't get Switch.co to do this, or they don't have the infrastructure to do so.  Anyone have any ideas on how to make this happen?