Depends probably on the nature of what "forwarded the costs" means.
If the business collected the costs from you and then forwarded them to CBP while acting as your agent, then you can demand a refund from them or sue them.
If you agreed to purchase goods for one price while also agreeing to pay a separate "tariff reimbursement fee" in exchange for purchasing the goods, you're probably shit out of luck.
Various shades in between might be arguable or litigatable one way or another.
Estimating the state of charge on a lithium battery is extremely complicated and difficult. And they stopped showing the numbers earlier because they didn't want you to see how inaccurate they were.
Nowadays, the models are better and more sophisticated, but the tradition continues.