Account Horror

I have an account with jet which i settled, on top of that i have a funeral policy with them but that is handled through a debit which I authorized when I signed my contract, now a year later I get this bill to say I owe and when I try to find out how I get lots of stories about migration, I have no problem with that if there was a hiccup,Ii request that they send me a yearly statement to reflect what I supposedly owe, they refuse to do that telling me that if I suspect ***** on my account I must sent them my details including a copy of my ID etc. otherwise they are threatening me with credit listing if don't pay, now i went twice into their store to pay with my ID hoping to resolve this matter, but apparently their policy has changed. also there is this bar code on their statement which you can use to pay but it seems some of their sales persons are still skeptical about their policy. By the way my contract has been amended without my concern to include a 20 month settlement period and I recall signing for only six months, there is also a jet club account added which I never signed for.! If there was a mix up with contracts because of their so-called migration why were we not advised accordingly? By the way how long does a funeral policy take to lapse for non payment? is it not after 2 months?