I'm sorry to hear that you're having difficulties pairing your Bluetooth. If you've already made sure that your phone's Bluetooth setting is set to "on" and that the Bluetooth headset is set to "discoverable," you may want to consider doing some basic troubleshooting on your phone. I've included the link to the Device How To page at the end of this post.
If that doesn't work, we can get you in touch with our team of managers, and they will do everything they can to help you out and get this resolved. Just send a private message to ATTCustomerCare by clicking here. Be sure to include your name, phone number, email address, and the best time to reach you. It might be a good idea to include an alternate phone number, just in case. Please keep in mind that it may take up to two business days to receive a reply, but this team is awesome and will work very hard to get your problem fixed.