Where is the money...?

I enjoy this platform, but a few weeks ago I made one deposit on this given day, I later realize there was three other deductions made. I send them the bank statement plus the transaction history to show the deductions does not match the deposits. Their response is I should contact the bank, because they do not make deductions (debits), which I get, but the deductions was made from the payment portals they use, so I expected some kind of investigation on their side, instead of telling me to contact the bank.