Believe me, JK, David had a hell of a time, due to one thing and another, but that's uncommon.
As far as I understand it, the 30 day cancellation period starts
when you request the MAC, not when they issue it. Hopefully you have some sort of record of that. Because of the billing cycle, it's actually very difficult to avoid paying the extra month, and you only have a window of a day or two in which to request your MAC, which you would have to carefully work out from the billing date, to avoid the extra payment. Clever, eh? ':| What Pipex
should do, and indeed, did for me, is to refund you pro-rata, so if you end up paying for a whole month, but only use a few days of it with them, they should refund the rest of the payment by cheque. Don't cancel the direct debit until the final due payment has been made, then definitely
do cancel it, or they may still try to take more (yes, they are that incompetent). If you are in a situation where they are claiming you owe them money, that will hold up the MAC even more. I assume the April 2nd payment has gone through? If you requested your MAC at least a few days before then, that should be your last payment, and regardless of when they now issue it, the May payment should not be due. Sorry, I appear to be rambling, but I hope that's clear.
As David said, your main priority at the moment is to get hold of that MAC, and then you can start to set yourself free. It shouldn't be, but it is a bit of a game, especially when dealing with a company like this, who seem to be so desparate to keep hold of customers, they are resorting to breaking the law. Get your MAC, and run for your life!