I guess you don't have a choice. That is a standard procedure and some airlines offer a currency conversion (just for info) but the final amount in your own currency may be different. The tickets are normally issued in the country and its currency whrere the journey starts. However it can be different, whichever the airline choses (in EUR, USD or GBP or even CHF) You can't dispute an amount that was showed to you. Same happens to us, if I pay the ticket in AUD and my card is in EUR, I will never know 100% the exact amount to be charged, unless the company gives the options to pay in our own currency (the total is then converted at the rate they please, and can be even higher as the bank int. chart) And if you refund the ticket which was paid in EUR, but you paid it in AUD, the final in AUD may be quite different from the one you originally paid - let's say the AUD has lost its value towards EUR in the meantime, so you will be returned less what you paid for, although the same in EUR what you were charged. Hope this helps.
When I need to buy a ticket that starts in different country that doesn not have EUR, I always use a OTA and choose my region, in that case you are showed exact amount in your own currency even though the ticket is issed in India, Canada or USA...