Cancelled our paid tickets without permission

Two friends and I had booked to see the matinee show of Mamma Mia. The friend who had booked the tickets came down with an illness and was unable to attend the show so she clearly stipulated that only her ticket needs to be cancelled. The other friend and I arrived at the show to be told that our tickets were cancelled by ticketmaster as well. You can only communicate with them via email, there's nobody to personally help you. Absolutely shocking. They cannot even read emails properly. What kind of people work for this company....clearly they don't care about their customers