Tui UK reservation for flight was messy

I joined many Tui tours such as trekking, cruises and even my honeymoon. I have always found sth to enjoy in Tui travel. But last month I had done a Tui flight booking for Zagreb and I was very disappointed. Firstly my confirmation email delayed and I had contact to Tui customer support and claim my refund. They told me I had already made my reservation but they did not give a Tui reservation code still. I have waited long time and 2 days before my flight, I finally had my code. I was so stressed.