funeral cover

My mum took out a funeral cover with jet in 2001. She always kept all payments up to date. Today she went into the store and according to jet the funeral policy was cancelled by them in 2014 because my mum's jet account was paid in full and inactive. Yet from 2014 until this last month jet has still accepted payment for the funeral policy. My question is why wasn't she notified of the cancellation of the policy. I think jet stores is being totally unfair towards the aged. Taking advantage of them by accepting money for policy that they cancelled. 15 years worth of payments are lost. What do we do now