Debit order dates

I'm soooo upset why sanlamsky debit me on incorrect dates I choose the 25th each month however this is not honoured they debit before the selected date resulting unpaids. I spoke to call center numerous times looks like someone is not doing their job. Call center is useless. I want the manager to call me listen to recordings and have my unpaid charges reversed as my debicheck mandate says the 25th not the 20th. How many time must I address the issue of dates. This is the only company with this problem or must I cancel my policies so I cannot claim. You left me as an unhappy client repetitive time now.