Physical banknotes did not move, just numbers in a database that keeps track of debt.
Your £10k is not 'actual money', because fiat currencies tend not to act as a store value over time, because inflation.
Currency is basically an IOU, or in otherwords debt. When you held the cash in your pocket that was a way of keeping track of the fact that someone owes you £10k worth of useful things, in exchange for all the useful work you have done. When you deposited the IOU's in the bank, that bank could collect the useful things that were previously owed to you, and the bank then owes you £10k. Instead what actually happens is the bank receiving your cash does not spend it, but uses it as collateral to lend ~£950k new cash into existence. The recipients then have a debt to the bank, but they also have a debt of useful things owed to them in exchange for the currency that was magically credited to their Mastercard.
"Your Money" isn't anywhere because it isn't money and it isn't yours since you gave it to the bank. All that moved was debt.