Trip.com complaint: bad service and problems with refund

i wanted to change my return flight ticket to another date. I choose the one with which i had rights to do so.
it took me 5 days until i gave up. here is how it works. I submited a request via phone or email, because their app not their website tool didnt let me do it. It showed up there that i dindt fly at all, so i need to change both in and outbound flights. Anyway i submit request, they send me email thta they received it and check with the airline. They came up with an answer that flight i chose was not available, although their agent on the phone told me it is so.then another trial.. it takes at least 12 hours, many times more, before they contact the airline, then they find an availble ticket and write me that they will check if there is any price difference with m original ticket and new one. Again waiting for hours…. Then i receive another email that amount i need to pay is XXX. i need to that i agree. Then they write me they will send me an email where i can click and pay and eventually change. email comes randomlym once in the middle of the night where i reside, once very early morning.. The problem is you need to click that link in that email in 30mins after arrival of the email. I miss the time, and then everything starts from the beginning. even if i chose the same flight it takes more than a day until i come to last step. And twice it happened that ticket was not available although theyy confimed that it was.
i decide to cancel it. This time there are alot of cuts and according to my claculations i receive 50 USD less then expected. Amount not paid a week, then i raise another ticket and this time they tell me amount is minus 20 USD.
I still didnt get my money back and never ever again with trip.com. this complaint will goto social media on all channels
I very storngly discourage you with buying from them any service.