Charged after my account has been closed. Account number ***

In my Edgars account I had a funeral cover, I paid in order to settled my account so that I will close it.i went at Edgars told them want to close my account and I told them that I paid my whole balance only to found out that they said I'm owing them money for funeral cover. As far as I know about the funeral cover when you didn't pay for it they automatically cancel it and they also told me that if I don't pay for this amount that I owe it will increase even if my account is close but I don't know how because I should l die now they won't bury me but why am I suppose to pay for?