3 friends and I were booked to fly from Havana (9 Jan) to Johannesburg (Landing 11 Jan) via Istanbul. We were unable to get to Havana and called Turkish airlines to request a change of flights to fly from Miami (instead of Havana) and connect to Johannesburg. We made more than 6 calls (on the 8th of Jan) being constantly passed from one department to another by the call centre agent. The last call on the 8th was 1h25 min with a gentleman named Mert 1) communicated 2 vastly different refunds amount for the similar tickets, 2) refused to give me a supervisor to help note that we weren't a no-show 3) Refused to give me a reference number for the call or give me his full names as reference for the call made 4) Kept me on hold for more than half the call until I hung up. The service is horrendous and there is a lack of consistent communication from the 6 differrnt agents about the same query.