********** transaction debited off my account for Old Mutual

On the 1st of June, I had a ********** amount of R902 deducted off my account the descriptor saying Old Mutual. None of my old mutual portfolios add up to this amount. I have made numerous calls, waiting up to 20mins per call, both my financial advisor and I have sent through emails to *** and *** which as gone unanswered.. My ID number is ***085. I want someone to investigate has to how this can happen and refund my money.