Pathetic Customer Service

I have been advised by SARS that they did not receive the payment for the tax due to my fund being transferred from the Momentum Retirement fund to Liberty Provident fund. I have on numerous occasions asked Momentum to send me the proof of payment for the amount of R12,146.70 in order to send this to SARS to sort out the issue, but for some reason, Refilwe Molaba does not want to send this to me. She is also not able to take my calls due to some technical issue. SARS is charging me over R8,000 due to them not having received this payment. Please can a manager or director get back to me URGENTLY regarding this. If I do not receive the proof of payment, I will be going to the Ombud as Momentum cannot prove to me that the money was paid over to SARS as they state.