A big surprise unfolded for a father-son duo in Bihar's Muzaffar as they visited a bank for pension-related work. Kameshwar Mishra, who receives a monthly social security pension of ₹1,100, was reportedly visiting the bank to withdraw his pension, when he noticed something pretty unusual - a bank balance of more than ₹700 crore.Kameshwar Mishra, who receives a monthly social security pension of ₹1,100, was reportedly visiting the bank to withdraw his pension, when he noticed something pretty unusual - a bank balance of more than ₹700 crore.The shock grew bigger for the duo as the same amount was reflected in the son's account as well, taking the combined balance to ₹1,500 crore, according to news agency ANI.The shock however was short-lived as the erroneous balance soon disappeared from both accounts.Here's what happenedKameshwar Mishra receives a monthly social security pension of ₹1,100. However, his account briefly displayed a balance of more than ₹700 crore due to an apparent technical glitch, triggering an investigation by authorities.He noticed the unusually high balance when he visited the bank with his son to withdraw his pension, according to news agency ANI.Also Read | ‘Who is buying ₹4 crore homes?’: Noida man stunned after property hunt exceeds his ₹1 crore budgetAccording to Mishra, the same amount was reflected in his son's account as well, taking their combined balance to over ₹1,500 crore.However, the amount reportedly vanished shortly afterwards, and both accounts returned to their normal balances.Recalling the incident, Mishra said he had visited the bank with his deaf and mute son to withdraw his monthly old-age social security pension of ₹1,100.After the withdrawal, he asked the bank staff to check his account balance, only to find them "stunned" and "astonished" by the massive amount displayed on the CBS system.He said the balance shown in his account was ₹7,59,69,51,951.16, and that the same amount was reflected in his son's account as well, taking their combined balance to more than ₹15 billion."I was naturally shocked by such a huge sum... I asked what had happened--how such a huge amount had arrived," Mishra said, adding that the incident caused him "immense mental turmoil" and left him "in a state of utter confusion," according to news agency ANI.Also Read | OBC quota, daughters' selection: Why Karnataka governor suspended KPSC chairman Shivashankarappa SahukarTwist after shock, amount vanishesBank officials reportedly verified the account details following the incident, after which the erroneous balance disappeared from both accounts.The incident prompted an internal inquiry to determine the cause of the incorrect balance display.Authorities have launched a probe to identify the source of the technical error that led to the massive amount being reflected in the pensioner's account.Further details about the glitch and the banking system involved are awaited.