It might not have even been Verizon's mistake. When you peer with an ISP it is the customer's router that announces the routes. Announcing all of your networks

It might not have even been Verizon's mistake. When you peer with an ISP it is the customer's router that announces the routes. Announcing all of your networks individually is literally a one line change in most router configs so it's an easy mistake to make. If the ISP is being defensive, and good ones are, they filter incoming routes to make sure they belong to the customer. But they may not have a filter that mandates that they're aggregated since that usually isn't a problem.