0/10 ! For 30 days since booking a holiday with Tui I have tried (on their Suggestion) to amend and upgrade my holiday on my personal Tui online account. Tui give prices for all options next to the 'apply button'. Every time I chose the options my holiday is increased by the wrong amount by over £200 ! For 30 days I have had hours of telephone conversations with 'customer' service & managers. At the end of every conversation they can't/won't explain why this happens and tell me someone will be in touch to do this within 72 hours (this never happens). I have send numerous emails and occasionally receive a reply long after 72 hours which bares no resemblance to my compliant. I have screen shots and a video of clicking the prices given and the wrong amount applied to the final total. I have told Tui and they won't explain why they do this. All the information I have has now been sent to Trading Standards and Abta who are advising me. I have used First Choice, Thomson now Tui for years and have never be treaded so badly. I will update or remove this review if Tui finally resolve my the issues as I think this only fair.