Calcium/Scale build up on opening

[DM]

My pool was opened today. I can't believe the condition. It is green, and the plaster is covered with calcium that is thick and covering every part of the pool. You can just rub your hand and it falls off. The plaster seems to be pitted. The pool is 4 years old. The end of last season we had some issues with the feel of the plaster, rough and bumpy. The pool store had me dump alot of Muriatic Acid in to adjust the ph and calcium, i guess. Three weeks of dumping Muriatic Acid then we closed. When we closed it the calcium hardness was 300. They said not to worry the draining and refilling over the winter will help. I'm afraid i might need to replaster. I ordered Ben's test kit today. The pool guy said my Ph is over 9 today. He said for me to bring a sample in tomorrow and to brush and vacume tomorrow. This is an inground 40x18 concrete/plaster pool with the deepest part beeing 6' 5". I need some good advise.