While I feel for you, I'm not sure why your upset. This is offseason and the coldest month of the year. That is why low crowds and cost to go. It is pretty well known that if you go around January/early February that there are going to more maintenance closures than at busier times.
The reason for annual maintenance is that there are so many moving parts that they break down often and they need the time to repair them and check all the safety equipment. In order to do a full inspection and repairs, they need to drain the water. Can't do that in a few hours.
Again, sorry you won't be able to go on. Splash is one of our favorites. We had a year we went twice, once in October and them again in May. Both times RnR was down pretty much the whole week(s). We were bummed so I know the frustration.