I have been trying to buy bus tickets from Ulusoy for travel from Istanbul to Safranbolu next week. I get to a certain point on the English version of website and a message comes up in Turkish in red saying "Acik Bilet Bulanamadi.......". Please what does this mean? I feel it would be easier for me to make a reservation now and then actually buy the tickets when we arrive in Istanbul. If we do this do we have to go to Harem otogar or can we buy in Sultanahmet? Thank you.