cost for Amending a prior tax return if expecting a refund

my 2019 tax return I had a refund, On 2020 I had to pay $3000.  On 2021 we had a refund. Looking back on 2020 we missed a 1098T for college tuition expenses and 1098E for fed loan interest. After making the ammend corrections it shows a refund of $2500 but it requires to pay additional $570 to process the amend. Is this seem correct?  Why we have to pay additional and even more than the original filing process if I am expecting a refund ? 

Thanks 

TGC