Joe Kilgannon , 24 , and Cezanne Bannon , 22 , are suing holiday company . Newport couple claim engagement was ruined by chronic food poisoning . Couple paid £2,000 for stay at Grand Bahia Principe , Thomas Cook , Mexico . Riviera Maya are investigating 'at present , unsubstantiated allegations '
Joe Kilgannon , 24 , and Cezanne Bannon , 22 , are suing holiday company . Newport couple claim engagement was ruined by chronic food poisoning . Couple paid £2,000 for stay at Grand Bahia Principe , Riviera Maya , Mexico . Thomas Cook are investigating 'at present , unsubstantiated allegations '