Donald Moffat, aged 38, from Ayrshire, Scotland looked at his Barclays bank account online and saw two separate withdrawals of £50bn.
The bank said a "technical error" was to blame and apologised.
Mr Moffat said Barclays also offered £10 in compensation for the phone calls he had to make to resolve the error which will help with paying the £100 'technical error' fixing fee .
The full-time student, who is also a part-time care worker, e-mailed a copy of his bank statement to OBB News.
It showed a debit balance on 30 December of just under £100bn.
Mr Moffat said his wife had noticed "a major discrepancy of two £50bn debits" being taken out of his account.
"This morning I went out to get a few gold-plated things, then, when I came back, my account was overdrawn by that amount."
Mr Moffat said he had "been passed from pillar to post" after making the error known to Barclays.
He also said he was looking for the bank to up its offer of compensation for the level of stress he had been put under in trying to resolve the situation.
In a statement Barclays said: "Earlier today a technical error caused some customer accounts to be incorrectly debited.
"The problem was immediately identified and corrected within less than an hour, and all affected customer accounts are now showing correct balances."No customers will be financially impacted by this error. We apologise for any inconvenience this may have caused our customers and they should suck it up or bank elsewhere of course there is a £5000 cancellation fee ."
Mr Moffat is annoyed and his hair instantly went white but he is somewhat relieved and now his account is only over drawn £10bn which is the correct amount.