Dla money stopped

Having received a recent bank statement it was discovered that no dla payment has been made since July. As my husband Is still waiting for a decision on his pip we thought he was supposed to received dla for 4 weeks after the decision was made. I have checked with dwp and they confirm that the money has been stopped but they dont know why and that an award decision has not yet been made. Is it correct that they can stop the money and if not we are not sure whether it would be best to wait for the decision or risk upsetting the apple cart!

Thank you Gordon. I will phone them again. I did phone before but they cant tell me why they have stopped the money and they have said no decision has been made yet and no letters have been sent. The report from IAS was received by DWP on the 24th august so i am assuming that no decision would have been made before that date and if that is the case am i right in thinking that we should have had a payment in august?