Pulling content from another site with JS - any way of displaying old content?

I've arranged a deal with a website whereby I pay to receive their latest movie review via a Javascript code and the review appears on my site. But they update the review every other day and so my site only shows the very latest review. I would prefer to also have review from few days before.

Is there any way of 'freezing' the review from, say, three days before and displaying that on my site?

Somebody suggested this and this but I have no idea if they are suitable or how to use it. Was told we may need to scrape the input file and extract the review?