Denied reimbursement of medical expenses by ESIC

Sir, My mother was suffering from cancer and undergone treatment from CMC Vellore. My father is a ESIC holder and thus claimed the cost of treatment as and when occurred. Earlier we had got 4 times reimbursement from the ESIC. But last two treatement bills was not denied on account of non-visit cum permission from the ESIC board of doctors. Is it possible for all labours or employee to read and learn the by-laws of ESIC? The patient is same and getting same treatment even from the same allowed hospital but yet denied. I had already lost my mother bcoz of cancer. Pls suggest legal action.