Priceline complaint: Flight cancellations

I booked a bundle through the Priceline- flight and hotel- I was charged the entire amount and received an email with a ation for the flights, and one for the hotel.
The flights were booked through delta, I tried to choose a seat with delta a few weeks after the purchase of the bundle and delta says they have no record of my flight or any record or my name at all.
At that moment, I call Priceline and they stated my flights were rejected and never went through.
My complaint is- why was I, the paying costumer, NEVER informed about this flight cancellation? Why was no communication sent letting me know that the flights were non-existent? If I did not take the time to call delta and see why I couldn’t choose a seat, I would have gone to the airport the day of the flight only to find out- I had no flights.
Another thing- they stated the never charged the amount for the flights, but my bank statement showed otherwise.
I was not given any options as to a credit, but only sit and wait for this refund and then purchase new seats- at which it would be too late.
The entire experience was emotionally draining, exhausting, and disappointing.
Not only did they fail to communicate that the flights were never processed, but they are still failing to return the money they charged and took.
The punished the customer for absolutely nothing.