Apple Watch

Huh? 

The Apple watch is unlocked and universal by default.

I'm not sure what you mean by " it was from Verizon"?

Did you buy used?

Did the original user factory reset it?

Are you setting it up with your iPhone?

Activate:

https://www.att.com/help/wireless/accessory-get-started/

Clearly you will have to call or chat with AT&T about the additional activation charges. 

Set up pairing

https://forums.att.com/conversations/apple/how-to-connect-apple-watch-with-cellular-att/5deffe06bad5f2f60604e88a

The Cellular wouldn’t connect after countless hours of doing what you described to do. Att said it was locked by Verizon.  I was charged twice for activation fees that I refuse to pay. I also canceled my internet services. I paid the bill, they refunded me the bill bc it was within 7 days, and they recharged me 125

Apple watches are not locked.

https://thegadgetbuyer.com/are-apple-watches-carrier-locked-att-verizon-t-mobile/

Hi there @conniwiley, let's meet in a Direct Message to take a closer look at the activation charges. It's the chat icon next to bell icon in the upper right corner.

In the meantime, here's how to set up AT&T NumberSync for Apple Watch (GPS + Cellular):

1. Go to the Watch app on your iPhone and follow the prompts to start pairing.
2. Select Cellular and then Set up Cellular. If you don't have a plan for your watch, you'll be prompted to select one. Be sure you have the AT&T user ID and password for the iPhone number you're using. 
3. Make sure to check the box and read the Important Information for NumberSync on the 911 screen.
4. Select Verify address. 
5. Follow the prompts to complete your watch setup.

We look forward to chatting with you soon.

Ashley, AT&T Community Specialist 

Never worked

That has nothing to do with AT&T. If the devices were blocked, not locked, it's probably because whoever sold you the watches did not removed their iCloud or had not paid for them, and they were blocked as lost or stolen.

You should have taken this up with whoever you bought the watches from.