Dissatisfied Discovery insurance client

I just took insurance for my car, they emailed the document detailing the cover. I called in to amend debit dates but the consultant argued that I should wait for the debit to go through and then call next week to change the dates. I’m the one who has to pay i know when I’ll be having money in my account but this consultant doesn’t want to understand we argued until my airtime got finished and he didn’t bother to call me back. I’m forced to cancel this insurance because I don’t want to be paying penalties for failed debit orderes