I really don't believe the refund was processed in EUR, but in USD. In summary, Global Blue gets to decide what bogus exchange rate to use for the card refund. I think the card refund is still better than the instant cash and commission there, but not by much. It is stated in the fine print, but they don't disclose the rate.

Essentially, from 21% vat original, you will get only 10 to 12% back.

The whole situation feels like a sham, but I know most people feel something is better than nothing.

My refunds are still procesing, but here are some examples.

Premier Tax Free (likely same as Planet Tax Free)
IVA 116.28 EUR
Expected 85.50 EUR
Posted card credit 86.19 USD

Planet Tax Free
IVA 24.16 EUR
Expected 16.50 EUR
Posted card credit 16.63 USD

Global Blue
IVA 23.70 EUR
Expected 16.84 EUR
Posted card credit 17.43 USD

Global Blue
IVA 10.16 EUR
Expected 6.14 EUR
Posted card credit 6.25 USD