poor admin, continuous double deduction

I am so disappointed , In June i switched to Miways from ABSA insurance and in July Miways deducted double and i contacted them to address the problem and i was advised that the payment will cover for two months i should not reverse for other month. I took their advice , to my surprise on the 24th August 2018 they deducted again. Something is wrong with their admin. It cannot be that difficult. I cannot always every month complain about double deduction. One other thing, my applications says deduction must take place every 1st of the month., why on the 24th . This is a nightmare and admin is extreme poor.