You ARE in control of your finances with DD.
You can see how much is going out and when.
You can cancel a direct debit, or set it up, online - if your bank provides online banking.
I am more in control of my money now than I ever was. I log in regularly to my account, check balances, make payments and manage direct debits, standing orders, direct bank transfers all from the comfort of my own home.
I am not at the mercy of Royal Mail, save on stamps and envelopes and get substantial discounts from the following for paying by DD:
Council Tax
Electricity supplier
Gas Supplier
Virgin
Home insurance
Motor insurance
If I am taken ill and rushed into hospital, go on holiday or any other situation, my bills are still paid.
I really cannot understand why people do like direct debits.