HELP

my 2 year old has been getting to spend time with her grandparents, (my in-laws). I try to tell them to stop spoiling her the way they do, ie: they let her sleep in their bed!!! and they dont disapline her at all!!! they let her run their house, i am in a bad spot right now, because i had a back injury so, they give me the break i need to rest and what not, but i cant stand how she comes back, she hits me tells me she dont love me anymore, what do i do?? i told them that if she keeps coming back like that then she is no longer aloud to go there, but like i said i need the breaks because of my back, HELP!!! is there a way to reverse their spoiling??