I was there the other week and they refused my work Amex but accepted my personal MasterCard credit card. Not sure your statement is accurate.
There are a small handful ah branches (see below) in tourist spots that does accept credit cards. In all other places, you should see posters apparently made by the staff that puts red crosses on Visa, MasterCard and AMEX logos near the entrance and/or the checkout kassa.
From https://www.ah.nl/klantenservice/onze-winkels/zelfscannen-en... (in Dutch):
> In sommige winkels kan je met je creditcard of buitenlandse pre-paid debetkaart betalen: de winkels op Schiphol, veel stationswinkels, de winkel achter het paleis op de Dam in Amsterdam en de winkel aan de Weteringschans in Amsterdam. Bij alle andere winkels kan dit niet.
It wasn't a branch that accepted credit cards (it was full of crossed off card logos), the clerk saw my foreign card with Mastercard logo and said that wouldn't work but I insisted by showing it had a Maestro logo on the back. Reluctantly they said OK, go ahead and for everyone's surprise, it worked.
The transaction ended showing up on my credit card statement, and to this day I really don't know what happened. I know that international withdrawals (that should use Maestro network) appear on my checking account. Who knows...