Termination of Membership

I have been a loyal member of Fedhealth Medical aid for some time. I want to terminate my membership with them effective 30 April 2016 as I am joining another medical aid effective 01/05/2016. But due the the fact that I have submitted my request on the 6th of April 2016, now they dont not want to terminate the membership.<br> <br> I know there is a 1 month waiting period, but i was late by a couple of days, I tried to pleased with them to overlook the days that i am late with, but they wont listen to me, i was on the phone with their agents and Even the Manager Melissa Naidoo who was just sarcastic towards me. How can I make them accept my plead.<br> <br> I was really happy with them till this date they don't know how to deal with people that are frustrated by situation.