How to contact Priceline?

Priceline's US number is (877) 477-5807.  You'll need your booking number or the phone number you used to book the trip.  If you used the same cell phone to book the trip the phone system will lookup the bookings for you.  Then you just press 1, 2 or 3 etc. for the booking you want if you have multiple bookings.

So what happens when you don't know your booking number?

Usually Priceline would send you such information to your email account but sometimes you're locked out of email or maybe you registered an invalid email.  In any case, use the phone number method.  Select your trip (by date) and then press 0 to speak with an operator.  The operator could tell you your booking number for future reference.

Note they cannot change your email address but they could forward a copy of your e-tickets and itinerary to another email address.
 
Also, if they need you to send in something; ie an ID photo or passport, you can email them at: airtsfax4@email.priceline.com.  Of course emailing sensitive information like this is not advisable as email is not encrypted.

Based on my experience, Expedia customer support is many times better.  Things are usually resolved on the first or second call.  For Priceline, I had to call them 5 or 6 times and each time the new person had no idea what the previous operator did so you have to re-explain yourself multiple times.

-spud