What does it take for the electric company to turn the service back on?

I paid my bill today after a shut off for non-payment. I payed and verified by noon. They never turned it back on. They do it electronically, I think... The same way they shut it off. Is this a dirty trick to punish me for paying so late? All my food will be ruined over the long weekend, and innocent people living with me suffer. Do they have have a right to delay??? I paid by NOON. What prevented them from reinstating me in the afternoon????