Max Life Insurance — Claims denied

When IRDA has said no company can deny any customer a claim if he I she has paid the premiums for last 8 years in my case I have paid for medical insurance policies since 2008 and maxbupa also says last 4 years if any existing disease s so how can a disease if its 5 yrs back and not related to this insurance company be denied I wnt all to know maxbupa is cheating everyone