Facebook - Refusing Funds balance refund

While paying for an ad on Facebook Meta, I must have mistakenly added an extra * to the amount to be added to my ad account balance, making the amount deducted from my bank as Rs*****, instead of Rs***.
Later I realized my mistake when checking bank statements for monthly expenses.

I contacted Facebook support about this, but they keep parroting the same line that I agreed to Terms and Conditions so my balance amount of Rs***** cannot be refunded.

I cited to them there own official site information where it is clearly mentioned that refund may be done on case by case basis (https://www.facebook.com/business/help/***************?id=****************), so my typo causing to lose me so much money should be considered as a valid case. They still keep repeating same TnC reason, with zero explanation.

This is a completely unethical practice by an MNC.