Stop cancelling my policy!

I got a call from Flexicare to say that my policy has been cancelled, again. This is the 2nd time that Flexicare has cancelled my policy for no apparent reason. They claim there was no funds in my account. I have deposited the funds on 30/10/2021 and 29/11/2021 for the debits to come off on the 1st. I'm Really getting sick of Flexicare cancelling my policy everytime, them claiming there was insufficient funds but, then they don't deduct the debits.