Moneris Solutions review: Credit card processing

Dear Moneris Complaints Department,
I am writing to formally complain about the handling of a fraudulent credit card attack against my small website.
My website experienced approximately 52,000 attempted transactions, occurring at roughly one-second intervals. Most transactions were declined, but eight were approved. Once we were notified of the attack, we refunded all the transactions we could, with one refund remaining unsuccessful.
I understand that fraud prevention and risk management are necessary. However, I am very concerned about the financial consequences of the way this incident was handled.
I was informed that the deposit associated with the approved transactions was being held because the transactions had been identified as fraudulent. Despite this, Moneris debited my bank account for the refunds. This caused my bank account to become overdrawn and resulted in a $50 NSF charge.
If the original settlement funds were being held, I need a clear explanation of why the refund amounts were not offset against those funds, and why the refund debits were instead collected separately from my bank account.
I request the following:
A complete reconciliation of all eight approved transactions, including the original amounts, settlement status, funds withheld, refunds, processing fees and related bank debits or credits.
A written explanation of why the refunds were debited from my bank account while the original settlement funds were being held.
Confirmation of where the withheld funds are currently held, the reason for the hold, and when they will be released or applied.
An explanation of why the remaining refund could not be processed and what steps are required to resolve it.
An itemized breakdown of fees charged on the attempted transactions, approved transactions and refunds, including which fees are refundable and the contractual basis for any fees that cannot be reversed.
A review of the fraud-prevention measures that were active during the attack and an explanation of what additional protections are available to prevent a similar incident.
Reimbursement of the $50 NSF fee incurred as a result of the refund debits, together with a goodwill review of the processing and refund fees associated with this exceptional fraudulent activity.
I acted promptly and responsibly once I became aware of the attack. I should not have to bear an unexplained cash-flow burden while the funds associated with the same transactions are being withheld.
I am a small business, and the impact of this incident is significant. I am asking Moneris to investigate the accounting and settlement of these transactions, provide a clear written response, and consider a fair financial resolution.
Please treat this as a formal complaint and confirm the complaint reference number and the process for further escalation if the matter cannot be resolved.
I look forward to your written response.
Kind regards,