Daycare Blues...Need Advice from Providers?

I run a small baby daycare with only 3 babies. Had them since they were 4 months old..now 2 years old. I was doing hourly pay rate but all of a sudden, parents got comfortable and making their own schedules. One had weekly schedule with M thru Fri. from 6:30am to 6pm. Ok , I got up early to prepare for the baby Monday Morning and the parent did not show up until 10am. This is not the first time it has happened. SOmetimes, they get off work early but decide to leave the baby a couple of more hours, lets say a total of 12 hours, cuz they want to go to dinner or shop. Ok, thats fine and dandy but when I am scheduled with 2 other babies and have to work around their schedules in order not to be bombarded with all 3 all day, a set schedule is very important. Plus, they only end up paying me $12 more. WOW..so now I started a weekly rate contract. No matter what , you pay that fee at the end of the week but they have to state if they are part time or full time care. Now they are mad at me..hmmm...what do you think.