Issue with Copart and sales tax paid on vehicle

I purchased a vehicle from Copart in July and in the invoice they charged me sales tax for the vehicle which I purchased in Arizona, however I currently reside in Texas so when I registered the car in TX they charged me sales tax for the vehicle here. They're now denying me a refund because the form to request a refund Arizona Form 5011, requires that I need a 90 day temp permit for the vehicle but I was only given a 30 day permit while I was there by the place I went to. So now they're saying I need to figure it out with my DMV and won't refund me the sales tax. What do I do at this point? I want to figure this out before I go to the DMV and end up going in circles again