Ioana In other cases the country setting turned out to be the issue, so that should work.
On the matter of the kind of card, please make sure that the stores and ATM's accept your card type. Maestro is knows to be poorly accepted outside of Western Europe.
When you have Mastercard, it can be useful for us on Together to know which error is displayed in your app under Events. As we are not the Support team, we don't have access to your data.