(Reuters) – RBS and its retail banking unit Netwests online systems and debit cards failed on Monday evening as customers were unable to process payments on one of the busiest online shopping days called the Cyber Monday. Millions of customers across the United Kingdom were unable to withdraw cash, pay for goods or use telephone and online banking services. In its response, the banks twitter account, RBS Help tweeted we are aware of some technical issues and are working hard to fix them. Sorry and thanks for your patience. The banks Irish unit, Ulster Bank, also reportedly faced similar glitches.