Charges from years ago!

Discovery Health... Why are you saying we are liable for charges from 2013 now that we are cancelling our medical aid due to immigration! 2013, 2015 and 2016???????? I'm sorry but No! If there were charges due from those years why were we not informed? You will not receive a cent until we have a satisfactory answer, plus we are now in New Zealand, but I expect a phone at a reasonable time to sort this mess out! We are doing the right thing thing, so can you!