PIP decision not matching my evidence

Hello,

I recently got awarded PIP for 3.5 years. I got the highest rate for both components, but I was surprised by how they scored the mobility part. I put on my form that I can walk 20-50 meters and sent a letter from my GP saying no more than 50 meters that I used for a bus pass application. However, I think that letter may not have been considered by DWP as it got there just a couple of days before they made a decision on my claim.

I was expecting to get some points for the 1st mobility question and 8 for the 2nd question (where you get 8 if you can walk 20-50 meters, 12 if you can walk 1-20 meters). I got 0 points for the first question and 12 for the second question, my assessor said I could walk 1-20 meters. It's making me a bit anxious - I wouldn't have gotten the enhanced rate if the assessor had stuck with the 20-50 meters I put on the form. What if in 2 years when I have my review someone looks back on my previous evidence, finds this GP letter they probably didn't consider now and decides I need to give 3 years worth of PIP back?

I didn't have an in person assessment, just an out of the blue 15-minute phone call where admittedly my assessor did insist a lot on the walking question. And I do tend to downplay how hard it can get on paper- the GP letter only says no more than 50 because I told her to say that out of fear if I put 20 they may think I was exaggerating. So I am thinking the assessor may have decided to disregard what she saw on paper based on her discussion with me over the phone. But I am still a bit worried.

I considered reaching out to PIP and see if I can get any clarification, but I am honestly so physically, emotionally and mentally exhausted after the whole application process (I got it first try with no reconsideration needed, but it did take 6 months) that I am not sure I have it in me right now.