I filed a dispute for theft but is this number legit?

I filed a dispute for vehicle loan theft with Toyota through transunion. A week and a half later I got mail from Toyota asking fkr additional information to support my claim. Planning to Fax the paperwork. But upon googling and going through the Toyota reddit found the # for Financial services is different than the known one online. # give is (866) 420-8723 for their "investigation unit" is this legit? Should I be cautious?