Last night we reserved a table for 15 people to celebrate a friend's 30th birthday. We made a reservation far in advance for 730pm.Most of us moved from the bar and already had drinks. It took a while to get a drink order in, the rest of us did not get our drinks until about 830pm.We ordered appetizers and those came out before our drinks even did.We were trying to be understanding and wanted the server to take his time. Most of us ordered wine but there were a few specialty cocktails in the mix, which we knew took a lot longer to make.All 15 of us work at a restaurant too, and we could tell he was busy. The restaurant had a few other big parties. We finally get our drinks, and we don't get asked to take our order until about 9.We'd already been sitting for an hour. When the food was delivered we were all very pleased, the food and drinks were amazing! No complaints there. We also had a cake brought in from elsewhere, and we were told when we made the reservation that there would be a charge for that. We all knew the deal, extra charge to bring in product, that makes sense. This is where things really started going wrong. The manager brought the cake out then said he had to 'Go deliver one thing for room service, then be right back to cut the cake'. He was gone for about 45 minutes with the cake! I don't understand why they took the cake, our server could of at least cut it. We also would have happily done it ourselves at the table if given a knife. We had all made other plans that night after dinner, but we were already missing them because it was about 10 by the time we got the cake actually delivered to our table in pieces. One of our guests had to leave and asked for her check before the cake was even brought it. The waiter still hadn't showed with her check. She asked multiple times about it. He finally came out and asked what everyone had. We were very understanding that it is hard to split checks. We told them on the reservation that it was going to be separate checks, so we thought he was separating them as taking orders. Our assumption of this was clearly a mistake. He took more than 45 minutes to get us our checks.We finally went to find a manager to ask him to help our waiter but we couldnt find a manager anywhere, we spoke to the front desk at the hotel and the concierge said he had already left for the night! She went to find someone else.A manager was sent to our table eventually, not even the same manager that cut our cake. He walked over and asked who wanted to speak to him. We kindly explained we just needed our checks so we could go and he said, "Well there are 15 checks, this would be expedited much more quickly if it were all on one check!" He was very rude about it and said that our server was almost done separating them and he'd be over when he was done. The manager was 100% correct that it would be quicker to do it on check, but we stated we needed separate checks from the beginning and even told the server exactly what everyone ordered at the end of the meal. Plus, there is no way it should take 45 minutes to separate checks, he could have been working on them the 30 minutes we were waiting for our cake to be cut! We simply asked the manager to help him as clearly he was overwhelmed. When we finally got our checks they were still all completely wrong. Someone even had an extra glass of wine on their check that she ordered but never received. At the end of it, we just all paid the wrong bills because we needed to leave. It was already past 11. Our server was clearly overwhelmed possibly a new employee. Management should have stepped in and helped him. We all felt very bad for him and tipped him well. He even took off the cake charge for us. We appreciate all the hard work our waiter did, he deserves better management that is willing to help him.We spent almost 4 hours at the restaurant, mostly just waiting. By the end of dinner none of us were pleased and the birthday celebration was ruined. We wished to resolve this before we left but the manager was no help at all and walked away from us