Disputing $500 Single-Day Data Roaming Charge. Requesting Retroactive Travel Pass Adjustment

I am disputing a $500 pay-as-you-go data roaming charge incurred over a single day. I was unaware that my line defaulted to pay-as-you-go rates rather than the $5 Canada/Mexico Pass. Paying $500 for one day of data is punitive bill shock. I am requesting a one-time courtesy adjustment to waive the pay-as-you-go data charges and retroactively apply the Travel Pass rate for that day, while paying my normal monthly base bill.