[Closed] My first ever work problem. Help.

Early this year I had a performance review, came out of the blue and the result was devastating. My branch has always had very poor stock take results going back decades. But the gist of this meeting was that I was the main factor. Although I've only worked here four years?
However not a single fact was presented to me, just hearsay and it seems.
My conscious is clear. But I know our administration and following of the system has been poor. This is mainly due to lack of staff, last year there were four of us instead of the required eight.
I should say I'm not involved in admin as I'm pure sales.
I had another review and it was the same. No facts. But this one ended with, if the stocktake figures are bad this time you know what'll happen. And there it ended. I've taken that as meaning dismissal.
I'm on top of my game, but I can clearly see the system isn't working. Therefore the figures will be out and so will I.
I've asked about a move, but I love my job and and have superb relationships with staff and customers.
I tried to talk tonight, but was shown the door when I brought up the subject.
I do wonder if its an issue of age. I've been in the trade since school, and my manager is a 23 year old grad with no experience.
Who do I turn to as I feel I'm being pushed?