It has happened to me twice in last two weeks. Bank Branch cant just say that they cant do anything about it, its there job to chase it up with Head office on your behalf. You dont need to write to Head office until and unless you have decided to make an official complaint. If you dont chase it up with Branch then they are not going to do anything about it. I had emailed CEO of Lloyds and also made complaint to Financial Ombudsman. I got two replies back with two different reasonings.Also I know 5 other people in my friend circle whose Lloyds account has been blocked in last one week.