> I made a significant payment recently with cash and the only bills the bank would give me were 50€ bills

All the ATMs I've used (across Europe) recently have at least offered me a choice of bills (notes) when I make a withdrawal.

I took €300 out of a cash machine in Italy yesterday, didn't specify the bills, and got it all in €20s... left me thinking the machine must have had lots of them and wanted to shift some :)