NO REFUND!!

I ordered a Groupon Deal about 3 weeks ago. I paid money into their account with reference number. I emailed them to ask why the deal went from processing to completely missing from my account. They told me that the payment failed and they will refund me. It has been several days now and I have not heard anything about my situation. I sent my banking details and proof of payment. I would like to be refunded as it was a substantial amount.