Home > Contact Get the help you need. Call us at 866.GAINSCO Mailing Address GAINSCO Auto Insurance P.O. Box 869153 Plano, TX 75086 Bilingual GAINSCO representatives are standing by to assist you Customer Service Need assistance? Call us at (866) 424-6726. Monday-Friday, 8 AM – 6 PM CST Claims Call us to report a claim or submit and manage claims online 24/7 Make a payment Make an online payment right now or call us to make one over the phone