Pathetic cancelation of policies after ONE unpaid premium

I have been paying for my 3 children`s policies for years now and unfortunately had to change banking details recently due to change of bank. It has been a month now and I AM STILL NOWHERE!!!!The policies have apparently lapsed due to non payment of ONE premium, yes only One, and I have spoken to the very clever consultants at Discovery myself after getting nowhere and all of a sudden i must now pay FOUR premiums to have the policy re-instated. What a load of bogus!!!!I am only two premiums in arrears due to the delay in service but I must now pay FOUR??????????? Why can`t the policies be reinstated with normal premiums and a double in December as I have requested a month ago?????