Grandparents

I have 3 children: 4yrs, 2.5 yrs and 12 months. My children's grandparents are a huge part of their lives. They love them deeply and so the grandparents have a very strong influence on behavior. Unfortunately, there are several things that they do that is against our family culture. They have introduced name calling (silly names, but still not nice), sneaking sugar foods and skipping naps, buying big expensive toys while we are decluttering our small house, watching media on cell phones because they don't have access to TV/ movies….the list goes on. They have good hearts but do not have good judgement or any type of "limits". They come to visit about 2 times a week when i have to take someone to a doctor's appointment or other important task but it is difficult when they leave because of the discipline issues. My husband and I talked about not leaving the kids alone with them but that is really complicated because we have never created a backup plan for childcare. Another element is that I am beginning to do homeschooling which I am having trouble being consistent with. We have spoken at length with them over these issues, but they just don't get our vision. This is hurting our hearts because we love them and want some sort of balance. At this point, I am getting discouraged. Can you please help me with a healthy point of view?