PIP award

i advised DWP of a change of circumstances & they confirmed they had received my form 5/6/17. I then had a medical on 28/07/17 & then a letter dated 14/08/17 to say they had everything that they needed to complete and make their decision. I have telephoned twice and the first time there was a automatic message which said decisions are usually confirmed within two weeks. The rude advisor told me they had backlogs and could not provide a timescale. I then rang again two weeks ago & the message had changed to say decisions are usually within four weeks from medical assessment. This time the advise was more polite but again she could not give any timescale for a decision. Is there anyway I can escalate this?
once the decision makers have the information all they have to do is add up the scores as they should have all the answers and each answer has a score depending on if you can or cannot do a specific task!