Insurance company advertise shares,Giant saw the advertisement and sent a mail(letterbox) for buying 100 shares, the insurance company reply back by

Insurance company advertise shares,Giant saw the advertisement and sent a mail(letterbox) for buying 100 shares, the insurance company reply back by saying 100 shares were fully allotted to him and letter of allotment was posted but it lost in the way and grant did not receive that.After several years he got a call to pay 400 fines , he refused that he was consider shareholder or pay fine