In a DMP creditors can do what they like - as I keep saying you have no protection from creditor actions. But in reality most DMP companies will tell you that this rarely if ever happens.
I deal with a lot of people who have tried DMPs, who have changed their minds because they see their debts not reducing or even increasing due to ongoing charges. And there are creditors who will continue to call - but this also can happen once an IVA is in place as well due to incorrect communication lines within the banks themselves.