I bought an apple watch from a person and he would not disconnect the activation lock. how do i connect to the watch now?

If the seller refused to disconnect the activation lock, then I would guess it was not their watch to sell. I’m sorry this happened to you but I’m afraid there is nothing you can do except, if you have their name, report them to the police. If you purchased the watch off a service like Craig’s list to FaceBook Marketplace, report this to the authorities there.

1. In the future, if you are considering the purchase of a used Apple device, read the article below carefully. Bottom line is this - Without the Apple ID and Password from the previous owner, no Activation Locked iOS device can be bypassed by you. Period. Don't come here asking how. It can't be done. The FBI couldn't do it. And if they couldn't the chances of you doing it are Zero - Zip - Nadda.
2. Do NOT call Apple or go to an Apple Store and ask them to unlock the device. Apple will NOT help you unless you have the Original Purchase Receipt with the Serial Number of the device plainly printed on it.

The All Too Common SAD Reality of Buying … - Apple Community