Typical Daily Mail selective reporting. What the National Audit Office actually reported was that:
(a) the United Nations set a target figure of 0.7% of gross national income for developed nations to contribute to help developing countries ;
(b) in 2010 the Coalition Government entered into a commitment to achieve that target ; and
(c) during 2013 that target was achieved.
Yes, the NAO did note difficulties in getting the OECD's January-to-December accounting year to fit in with the Government's April-to-March one, with 40% of the Department's 2013 spending occurring during the last two months of the year but much of that spending was in relation to urgent crises. (e.g. 40% of the spending during that period went to Syria).
http://www.nao.org.uk/wp-content/uploads/2015/01/Managing-the-official-development-assistance-target.pdf