Viagogo AG — purchase of concert tickets

We recently purchased concert tickets through Viagogo website and have been trying to sell them back through the same site as per their instruction procedures. However, the site is refusing our request on the premise that there is not enough time to deliver the tickets for an event in August 2017. Have been trying to establish contact with their customer service department on numbers provided, however these numbers are all computer generated recordings and does not apply to our situation. There is nowhere on the viagogo site listed a direct telephone number or email address so it is impossible to actually speak to someone. This has left us feeling we are dealing with a shady company. Would appreciate your assistance or guidance.

Address: viagogo, Rue de Lyon 109, 1203 Genève, Switzerland
Company Number: CH-270.3.014.628-0
VAT Registration Number: CHE-247.099.716 MWST

Regards
Tony Scerri - Malta