Asking for the contractor's license # is always good. But if you really want to jack them around, first tell them that you want to get the free estimate. Then tell them that you need to get their contractor's license number before they come. When they say they will provide it when they come, say you need it now. You could also offer to meet them at a nearby Starbucks so they could give it to you there.
12/09/16 12:31 PST Apparently, even though I told them the last time that I already have a contract with someone, they tried again. Since I was out when they attempted to call and I blocked the number the last time they called, I am hoping it only rang once and disconnected them.