Title Tag and Meta Description Not Updated on Google

So the summary goes like this:

1) I create a page on my website with a title tag & meta description

2) Duplicated the pages 10 times as placeholder (all random title tag and meta description)

3) 10 pages were indexed on Google

4) I changed the title tags & meta description 1 month ago

But up to today, the old title tag and meta description still shows! What is happening? Submitted the URL to google 2-3 times, but nothing happened.

Any help would be appreciated!

You want to keep links and just change the meta?
It seems, it is not yet indexed as you are able to visualize the cache copy.
How about using some link indexing websites? which will help you to index website with latest meta.
For eg: You can use free plan :

Select Drip feed and adjust the total number of URLS accordingly.

Do this and let us know the results after 7 days.