Poor after sales service

Bought A Ryobi line trimmer form Game Cradlestone Mall on 27 January 2020, it broke into 2 pieces in August 2020, unfortunately I misplaced the till slip but went to the store twice and gave them the exact time amount and date of my purchase, but they cant seem to find the transaction on their system. Now I only have a month before the warranty expires and they just pull up their shoulders.