The prize was won in New Year's Eve Raffle draw and must be claimed before the 180 day deadline expires. If the prize is not claimed by the close of business on June 04, 2014, it will be too late and the prize will be allocated to National Lottery Good Causes.
The winning selection is GRN686516. Does one of your old tickets bear this selection? If so you should contact the National Lottery Line on 0845 910 0000.