So my dad has been overpayed £6,000 since 2004 for pension credit. He was unaware that you cannot claim it if you get a private pension which he does. He's not all there tbh but nothing diagnosed. The DWP asked for information in 2013 which he says his bank sent the information (when Scottish widows operated in Lloyds bank)......DWP say they never received anything and continued to pay the pension credit till now??????? What to do???