St Andrews requires 3.5
UCL requires 3.3
Glasgow & Manchester requires 3.0 so you should try these two instead of the above 2 as your GPA is below 3.3 and 3.5 that they require
Just check the website for yourself
1. https://www.st-andrews.ac.uk/study/entrance-requirements/thailand/
2. http://www.ucl.ac.uk/prospective-students/international/countries/south-east-asia/thailand
3. http://www.manchester.ac.uk/study/international/country-specific-information/thailand.htm?page=2
4. http://www.gla.ac.uk/international/country/thailand/#/

This might not be what you have anticipated but why not try some universities that are ranked a bit lower and aim for a scholarship. I got offered by LSE & St Andrews but later went to Sheffield as they offered me a 10000-pound scholarship which accounts for 3/4 of my tuition fees.

I finished my bachelor degree at UQ Australia and many of my friends went to Uni that offers scholarship rather than just focusing on prestige which also gives them a somewhat sense of pride.