Following is how we worked thru our flights to get a refund for our trip flying into 5/17 and departing 5/31 London Heathrow from Charleston SC. As early as March we began to become concerned whether we may have to reconsider our trip. I know our circumstances are different but maybe some of the following will help.
1. About March 20, we were informed that the Chelsea Flower was cancelled. We had purchased tickets and received a full refund. Our tour at Stonehenge was then cancelled. Watching the news and realizing that venues and attractions, transportation in London and elsewhere were beginning to shut down, we realized our trip was certainly futile and began to cancel all accommodations, the car.
2. Upon doing research and reading travel blogs, etc. we decided to not cancel our flights just yet, but see if the Airlines "blinked first" and cancelled the flights, ( with the intent to get a refund in lieu of vouchers, credit , for more travel flexibility in the future).
3. On April 13, flights had not been cancelled but we received an offer from Expedia to reschedule our trip or get a voucher without penalty. They urged that would make it EASY for us. LOL I did not blink but continued to wait as the situation in England sadly deteriorated. I checked airlines and saw that our identical flights were not showing up on daily schedules, i.e. beginning to be cancelled.
4. On April 21 we received word from Expedia that our flights had been cancelled and they had set up a "credit" for us. No thank you. I called Expedia to request a refund but was advised I had to wait until 10 days before our May 17 flight to make the request. I continued to wait patiently.
5. On May 8, I called Expedia and after speaking to two reps, got the refund rolling, although was told the refund was only 90% assured. Yeah right!
6. On May 13, I called the (American/British Airways) airlines just to see who had our money, Expedia or the airlines and was informed that Expedia held it and that they saw on my account record that a request from Expedia to confirm flight cancellation had been made.
7. On May 14 I called Expedia to "check on the progress of our refund" and was told that it was in progress and we should see it applied to the original form of payment (credit card) within 8 weeks.
8. Surprise!!! On May 15, the full refunds showed up applied to our credit card. Yeah ... worth the patience, and not an 8 week wait after all.
I guess what I am trying to get across here is that you should scope out the situation in Croatia, see if it is worth taking the trip now with so many restrictions and closings. Can you even get into the country? Will there be a mandatory 14 day isolation when you get there, as there is in many countries? etc. Check the same flights that you have for 6/15 and see if they are flying out now .... if they are being cancelled now I will bet that trend will continue into the near future. Do you have the patience to see if Lufthansa "blinks" first. At all times, I tried to be very calm, civil, polite and thankful for info from Expedia and airline reps ... they deserve it for what they have been thru, and it will smooth the road for an efficient refund. According to FAA regulations, if flights are cancelled you are by law entitled to a refund. Though with financial stresses, the airlines will do what they can to get you to take a voucher/credit, reschedule. Have you got the patience to wait a bit longer? Is a credit or re-schedule OK for you?
I had a good experience with this but it was really tough waiting. I apologize for the length of the response ... just needed to provide some detail which I felt was important.
Good luck, Marianne