In 18 years of travel, I cannot remember such inefficiency.All I asked for was a change to my ticket.
I called 8 times, sent 5 emails, even visited the local office. They kept saying yes, we will, then did not even bother to call back.
I had to endure 7 hours more on a 2nd connecting flight and collect and recheck in my bags twice! They are slow, inefficient, not knowledgeable, untrained, just give any answer to end the call.
Managers do not get back to you on time. Be prepared to have a lousy, frustrating experience if you use them. If it goes smoothly, it is just by chance, not because of the company. Use the airline website directly, much faster, better customer service.