PIPAward

Hi, any advice would be greatly appreciated.
I have just had notice off PIP that I have only been awarded the lower rate care allowance. I can barely walk due to arthritis in my lower spine, I also suffer with arthritis in all my main joints, I struggle with everything due to the pain and the restriction of movement.
When doing the Pip assessment I should technically be awarded high rate on both mobility as well as the care. I cannot believe that I haven't even been awarded any of the mobility award. I will appeal against the decision, but was wondering if this kind of decision is happening to new claimants. I don't understand why I have not even been awarded any mobility at all. I used the info on this site to help me fill in the paperwork, not that I'm blaming any of the info provided of course. I have had a telephone health assessment and answered all the questions accordingly, keeping to all I had wrote on the form about my mobility issues. Thanks in advance.