Pip mandatory reconsideration

I have a dilemma about a reconsideration decision which just arrived earlier than expected and wondered. whether this is quite common. I act for my son and the original decision was to award no points. I phoned to request a reconsideration and was allowed a little more time to send any extra evidence. The original date given for this was 2 October but before then I asked if I could have a little longer as I was finding it difficult to to get all evidence plus my personal statement together. This was said to be not a problem and I was given an extra 2 weeks. Before I was able to send my submission and evidence, however, I received the reconsideration report dated 28 September which resulted in award of 9 care points giving the basic care award. I had been making a case for the enhanced rate but I now think that, as the decision has been made, I would have to appeal so will probably accept the basic rate. It just really annoys me that agreements to time extensions are apparently noted but not acted upon. I am assuming, but would like confirmation, that you cannot ask for a second reconsideration because of this maladministration. I would not want to ask ,but it would have been different if the original decision had not been changed. There is a degree of relief that needs have been recognised to some extent and I can forget about it for a couple of years.