I was completely in crypto, but I believe that conversion of fiat into crypto is fairer to fiat holders than anything. If they don't want the crypto at current rates, then give them the option to only get tokens. You don't seemt to have dollars, so you can't return dollars to them.

You can then use the crypto that was refused to refund the crypto holders.

There is no 100% fair solution. We are all on the exchange to profit of crypto rising, but BTC could just as well have crashed after August 1st.