I'd contact the owner of the daycare. Discuss with them the situation, state in no uncertain terms that your child will no longer be attending their daycare because punishment for misbehavior should not mean them missing a meal. I would also let the owner know that you were going to give every parent you could get in touch with a head's up on the matter so that they knew what was going on there. Suggest that the owner correct it, but for the well-being of your child, do not continue using that facility for child care. It is simply inexcusable.

Demand of any future child care facility or person that if they need to correct misbehavior, the only permissible way they can do that is through time outs. If that doesn't work, then they should discuss any ideas for correction they have with you prior to attempting them. And under NO circumstances should their meals be taken away from them (delayed for a timeout at worst, but not by more than 5 minutes).

If there are any other circumstances surrounding why a meal was denied them or taken away, such as your child was starting a food fight, then those matters should be dealt with accordingly and you may consider understanding and being lenient for a reason like that.