Review of Marks rip off?

So, my son has just had the outcome of his WJEC R/S Hinduism A-Level papers back. We hoped that the ‘review of marking’ could potentially find the single mark needed to tip his grade from a D to a C. RS being an essay based subject, we thought it would be worth a shot. No joy- the overall grade remained the same.
We were disappointed. My son refuses to to accept he only got a D, so l started googling the review of marking process when it came to my attention that his scripts wouldn’t have been marked a fresh as one might expect. The exam board don’t actively re-mark the scripts at all, nor do they seek to add or deduct extra marks. The second examiner merely gives their final judgment on the initial examiner’s ‘reasonableness and appropriateness’. The process seems more holistic than technical. I feel that we’ve been scammed tbh.
Furthermore, from my understanding the exam boards don’t actually release the marking criteria till after the review deadlines for his teachers to cross reference- so we felt that we little choice but pay up.
So, l just wanted to pre-warn others that it seems to me the exam boards would rather protect their own reputation and their money over giving students the proper reconsideration that they’re expecting when they’ve worked hard and paid for professional service. Don’t get me wrong- l know that peoples grades do get changed, but my understanding is that it’s much more likely to occur due to clerical errors and total pages/answers overlooked and your more likely to go up in 4 or so marks due to an obvious oversight than get the single mark needed. Nobody ever told us this at his sixth form and l just wanted to make fellow students and parents aware because like grades, money doesn’t grow on trees.
My advice is to always view your exam scripts first before you take the gamble.

Hi, I had the exact same thing happen to me in august. I was 1 mark off an A star in an essay subject. I received my remark literally like 3 days after I requested it and there was no change at all. I am really annoyed about this as I had my scripts returned to me and I was told by my teachers that they would have given me more than 1 mark extra. It's so annoying. Did you find any other way to get the grade changed?