When we tried to meet and dine in the dining room, the check in lady was quite rude each time. If we told her we had say 12 people eating at that sitting and 11 were with us (with one in the restroom) she would make us stand and wait before seating us. She was just very rude.
The only good thing on the ship was we had a great waiter in the dinning room. It's not a ship or line I do often, and would not do this ship again.
Did you have the "your time" dining option? I've never selected that myself and have often wondered how that would work for us, especially when we have a large group traveling and dining together. For the hostess to be rude is most certainly unacceptable.
No matter which cruise line or ship we sail on, I always try to give credit to the staff for the number of days and hours they work. It's much more than I could ever do.
Later this month I will have the pleasure of my 10th Carnival cruise, and look forward to many more with them.