Groupon took my money and I got nothing in return

On the 11th December 2015 I purchased numerous deals from Groupon intended to be Christmas gifts. I waited patiently for a week, checking about 3-4 times a day to see whether the status of my purchases had changed from pending to sent or delivered. On 18th December when I went to check the status of my deals they had all disappeared. I have since then e-mailed groupon, received a ticket number but no response. I have been trying all morning long to get through to their call centre but I keep getting cut off due to \high calls volume". I am enraged not only at the fact that Groupon has taken my money without giving me my deals"