Having emailed IPC subs again, I got a reply from them saying 'We can confirm that you can leave your current subscription to expire and set up a new subscription under the promotional offer you have seen.' So that kind of makes it offical, don't you think - no point in renewing when you can get it so much cheaper as a new subscriber. I didn't have a direct debit anyway, in fact one year I did set one up but they lost it!!

Thanks for the tip about Tesco vouchers - that really is a bargain. I have a stash of Clubcard vouchers so that sounds like the best option!