Online purchase has just dissappeared!!!

On the 24th November I purchased a Bluetooth device from Groupon, the money was paid immediately, after checking yesterday it said the payment was unsuccessful, today the purchase has been completely removed, how is this possible? Nobody from Groupon has contacted me regarding this, I am extremely disappointed by their lack of communication. This is poor, especially as it's such a great service to use, and this is the first bad experience which might just put me off future purchases.