I think asking for free breakfast for 5 rooms is a bit much. How many guests are in each room?

I occasionally run into problems bending the rules at my place. A guest will ask if their nephew who lives nearby can come use the pool. Then it turns out to be 2 nephews, a niece, a couple of friends and then a birthday party.

If the hotel gives you the breakfast, great. But if they say no then they probably didn't have all the details they needed when you called the first time, like how many people were going to be eating.

EDIT: I also see you booked prepaid, which is discounted. That's not going to help your argument with the sales manager. Let us know what happens because if the manager gives you the breakfast then you really lucked out.