I booked my flight through priceline website and 1 week later my daughter wanted to join me so I called priceline to ensure she would be assigned a seat beside me on both our departure flight and return flight. The agent assured me that we were seated together. I called the airline 24 hours before my flight to check in and found that we were seated no where near each other and was instructed to call priceline back. I then called priceline only to be transferred several times and on the phone for over an hour. The representative told me I was seated beside her so I call the airline again while the priceline representative is on speaker phone to confirm this and again the airline states that priceline never confirmed my seating assignments causing me to lose the seat and the only seats beside each other would cost an additional $60.00. I talk to the priceline agent who heard every word the airline agent just said only to tell me there was nothing they could do because the initial priceline agent did put me beside my daughter but the airline has the discretion to change it. I told her, the airline did not say that and I know you heard them say priceline never confirmed my seats causing me to lose the seats. Again the priceline representative said there was nothing she could do unless I wanted to pay extra. I expressed I should not have to pay extra to fix their error and asked to speak to a supervisor. The priceline agent put me back through the que where I sat on hold for an additional 30 minutes. I will not only never book through priceline again but will ensure to tell everyone I know about my experience so that they may seek another source for their travel needs.