Incorrect Pension Details given to SARS by Momentum Funds at Work

I have been trying from November last year to get some sort of response / correspondence from them to show SARS that they have incorrectly advised SARS of R30000 which SARS claims I collected and they are taxing me for this amount .SARS requested a certificate from Momentum but their is no certificate issued cause i never collected any monies from Momentum. SARS has all the details of my pension etc. Now I am not sure how safe my pension is with Momentum. Each time a send an email i get a stupid answer and have to start my story again. I even phone various personal from Momentum but i have had no joy what's so ever