People just don't think about the dangers of Direct Debit- just Internet search to easily find out about the huge amount of people that have had problems, companies taking too much, the wrong time etc, making them go overdrawn and into fees (£30 for every bounced DD)& interest etc. Yes the DD guarantee IS useless, if you complain to your bank they almost invariably tell you to take it up with the company issuing the DD. Or if the bank even DOES (after much begging) get the money restored for you, did you know that the company can simply REINSTATE the DD amount and you'll have to go to your bank to get it reversed AGAIN. Banks have even admitted to distressed customers "DD originators have every right to reinstate DD amounts if they believe they have an outstanding unpaid debt!!!!" (And there was me thinking the money in my account was mine and what gets paid out is under my control- no longer true once you sign a DD mandate!) The astounding thing is that once anyone has got your sort code & AC no they can put it on eg any charity donation newspaper form and set up a DD- the bank doesn't check the signature or anything at all once the details are transmitted electronically to them by the charity's bank. (I learned this from someone who used to write DD software for banks). Please check out this very telling article http://news.bbc.co.uk/1/hi/7174760.stm The onus is on YOU to notice the payment you didn't authorise! That's how wide open the system is that the all powerful commercial banks have unleished on us permitted by our supplicant and negligent governments.
Moral of the story: Don't EVER give your AC details on DD mandates to ANY company you need to pay, use standing orders (which YOU have total control over) to pay them or electronic banking (where you ring your bank every time you get a bill) to transfer the money, or pay by cheque the bill at your bank branch or at a PO or by post. Carefully guard your AC numbers and watch your statements like a hawk every month.
One final point how do I manage to avoid DD (where I live in the UK) without being penalised? Answer: 1) My UK gas & elec ACs are with Scottish & Southern energy EQUIPOWER tariff which charges everyone the same low tariff HOWEVER they pay. 2) My landline phone- I ditched BT as soon as they started penalising and changed to Post Office homephone exactly the same service, copper telephone line & exchange equipment & IN ALL ASPECTS (line rental & free periods) CHEAPER than BT & no extra charge at all for paying by cheque at any post office- EVERY bill.3) Council Tax & Inland Revenue charge nothing extra for paying by cheue either at your bank, the PO or by post. 4) I don't bother with Gym membership- I just WALK a lot!, 4) I take the risk and don't bother with AA or home insurance as I am an engineer and able to forecast and carry out all my own home repairs and build in stiff burglary prevention measures, locks alarms etc.
Stop doing what you're told people- think about the possible downsides later when the commercial companies suggest to you ways of doing things that benefit them. Telling you the upsides but not the less obvious serious downsides.