Viagogo Overcharges For A Concert in Greece

I recently bought 2 tickets for the ΠΥΞ ΛΑΞ concert in Greece through Viagogo. For these two tickets I was charged a total of 64.24 €, as shown in my Viagogo order confirmation (order number 653071925). Right after completing the payment, I checked the same concert on the official ticket seller More.com and saw that 2 tickets for the same event and category were being sold for a total of 34.00 €. I have saved screenshots from both Viagogo and More.com clearly showing this significant price difference for the same concert and ticket type. In addition, when I previously bought tickets shortly before an event from More.com, I received the tickets immediately. This time, after paying Viagogo, I only received a confirmation email and I have not yet received the actual tickets, which makes me feel even more insecure about this purchase. I request that Viagogo at least refund the difference between what I paid (64.24 €) and the price at the official seller (34.00 €), and ensure that my tickets are delivered to me in time for the concert without any issues. If this is not possible, I expect an alternative solution that fairly compensates me for this situation.