Is there some way to save next month internet quota when a download from Google Play Store fails?

Is there some way to save the next month's internet quota when a download from Google Play Store fails? The only way now is to prevent Google Play Store from failing a download, but that may be impossible. Why next month's quota? Because I was downloading several apps, each with about 3GB, and my internet provider throttled down my connection, so using the internet for any other than letting the Google Play Store download to complete became impossible, too slow. Then, using NetGuard, I blocked Google Play Store to be able to use the internet for everything else. But then, all downloads failed, the partial files got deleted, and now resuming the app's install will redownload from the beginning, which is totally absurd. So I thought: if we could throttle down the Google Play Store download manager or the connection to its site mirrors, like max 30KB/s (my max speed now is 250KB/s), we could prevent Google Play Store failure and so prevent messing the internet provider quota. So, I want to know if and how we can do that? How to throttle down Play Store downloads? The only other alternative would be to never download big apps directly from the Play Store, but use a coherent, smart, and decent download manager that can just resume later, and download from the app developer site or from some updated mirror. I did the same actions, to start a download, block the app in NetGuard, wait for it to fail, retry using the manual install option, with Aurora Store, and the download resumed! Despite showing no hint that it would resume. And not all apps are available there. But... the 2nd time it failed, I don't know the reason, the downloaded part was lost too. So just grab a download link somewhere else and use no store apps at all.