Group 1:
(844) 977-1174
https://delta-flightbooking.webstarts.com/
https://deltaairlines-phonenumber.webstarts.com/
https://delta-airlines-customer-support.webstarts.com/
https://delta-airlines-reservation-number.webstarts.com/
https://unitedairlines-helplinenumber.webstarts.com/
Group 2:
(888) 749-0047
No more 9 digit IVR and not sure if same group.
https://www.selfgrowth.com/articles/phone-number-1-888-749-0047-hawaiian-airlines-flight-reservations
https://www.selfgrowth.com/articles/toll-free-1-888-749-0047-hawaiian-airlines-contact-number
Group 3:
(888) 304-1535
(855) 929-5019
This could be them also, but I cannot confirm yet. The last number given here is listed there as well.