PIP phone 'helpline'

I recently phoned PIP about copy of Assessor's report PA4 previously requested following telephone assessment for PIP review. Unusually in my experience I spoke to someone who was very sympathetic and helpful. Confirmed request for PA4 was on system and I should receive within 1 week - now received. They suggested that the PA4 from initial claim in 2018 would be useful for a Mandatory Consideration and is sending copy of this as well. I had posted letter requesting MR that morning but operator offered to log it based on phone call - txt received within 10 minutes confirmed! Operator briefly checked original claim and suggested that review decision should be challenged....
Phone no. I used was 0800 121 4433 - nearly 1 hour before i got through to operator but well worth the wait