Best answer by woz
It is unlikely that PP have taken a DD that is extra (not saying it can't happen but that it's unlikely)
In any event IF they have you're covered by the DD guarantee, and a call to your bank will reverse it no questions asked (well almost no questions)
Before you do that double check what monthly payments PP have taken and that they haven't missed one, and it's worth checking with them to see what's happened (see other reply)
if they had missed one they should have informed you when it was going to be taken so if you've had no communication so that seems unlikely too.