Refund of premiums deduction whilst not covered.

I bought a FNB Health Plan 10year ago when I 55years old now I am 68years old I receive a notification from FNB that I am no longer on the HEALTH PLAN Because the HEALTH PLAN stops at age 60 which is 8years ago But FNB was deducting my monthly premiums every month for 8years and now tell me the news that the HEALTH PLAN STOPPED I ASKED FOR THE REFUND OF PREMIUMS PAID FOR 8 YEARS AND FNB SAYS I SHOULD KNOW TO DATE NO JOY WITH THE REFUND DEDUCTED.