My sisters appendix exploded! help?

so my sisters appendix exploded like 3 weeks ago, she had the infection and they drained it out with tubes. BUT she still has her exploded appendix inside her body because the hospital she went to is giving her the run around. The doctor who seen her went on vacation right away without giving her a follow up appointment so that she can get surgery and there is an insurance issue. she does not know when she is going to get it removed its been almost a month since, What can happen, what can she do.. I think this hospital needs to have legal action taken up on them... I dont know but i am worried.