Complaining comes naturally to elderly people, especially when they feel their decisions being taken over by someone else,    One of my tricks is using parents against each other ,or for.  We had to put a shower on the first floor.  We told Mom ,Dad needs it because he has had knees replaced.  We told Dad, Mom needs it she’s getting weaker.  You, may have to start with smaller steps.  I know its very frustrating,  they will change their minds a thousand more times.  My parents I started a cleaning lady once a week and am trying to increase it.  I tried a companion , interviewed her, checked referrences, etc.  My mother had an absolute melt down when she was coming to the house.  Good Luck.