"I rather give -5 stars if system allowed.
Priceline booking system is not reliable, and when they found it was their mistakes, they are very good at transferring their responsibilities to others or just disconnecting the call.
I booked two Delta flight tickets with seats selected in main cabin (my husband has claustrophobia so he must sit on the aisle seats) on 11/19/2021, and got conformation email on the same day, and credit card was also charged on the same day. 10 days after the reservation (one and a half days before our departure), I logged in Delta website but found that there is no any seats booked in all our four flights. Yes, Priceline DID NOT book any seats for any of our flights. I was in a hurry to reserved the seats, and contacted Priceline to question about this big mistake they’ve made. An agent name Ian told me that it because the airline doesn’t allow priceline to choose seats (latterly I called delta and confirmed that it is not the case. Delta accepts seat booking from third party website.). I then contacted Priceline again, and waited for over an hour to reach their escalating team, a representative named Avery, she then told me that in Priceline, also includes all other third party agencies, all flight bookings are not guaranteed for seat selecting. I asked her to email me this Priceline rule but she said they don’t have written documents for it. When I questioned her why there is no email to inform me the seats were not booked, she didn’t have any answer. When I questioned her about this discrepancy, she disconnected the phone line.
I have used lots of thirty party website to book flights for several years and every time I got the seat I selected when booking except this time through Priceline. Be aware, your booking through Priceline does not guarantee the seat you selected, and you will be disconnected when you push for answers.
Will never ever use Priceline again."