ITC without incurring the expense

A user's bank mistakenly charged processing fees twice, including the GST. While the bank refunded the basic amount, they refused to refund the GST component, claiming the user should claim Input Tax Credit (ITC). Other users debated this, with most agreeing that ITC cannot be claimed without a corresponding expense, despite the charge appearing on GSTR-2B. The original poster decided not to claim the ITC due to potential disallowance and interest penalties, and is asking the bank for a written explanation or the specific GST rule that allows claiming ITC on un-incurred expenses for bank charges.