Not sure what the cancellation policy is, but at 22 to 28 after tutoring and practice is doable. And a 19-20 for a kid just going thru the motions isn’t justification to cancel the good test. At the kid’s school, his first 2 years the ACT was mandatory. They gave practice tests to freshman and sophs. Then they changed to the SAT. We decided to stick with the ACT and he did really well. He still was required to take the SAT – but I think he slept thru it. 
Not so good. Hard to be motivated for a test that just doesn’t matter. I’d pursue it with the ACT people – make sure you talk to real people who can make decisions. Good luck.