so, ok, this is info on blizzards site in their own words.
Breaking News: Ongoing Slow Download Speeds
As a result of increased network demand on the internet at large, we’ve seen an impact on players’ download speeds when trying to install or update their games. We continue to monitor and adjust elements within our control to get these downloads to you as quickly as possible, while also working in a space with ever-increasing demand for bandwidth across the internet at large.
In an effort to maintain service and internet uptime for all customers, our Content Delivery Network partner is helping alleviate network traffic during peak hours. Some traffic may be deprioritized to ensure internet stability for all customers, which can result in slower download speeds for gaming downloads during high-usage times.
If you are experiencing slow download speeds, there are several troubleshooting steps we can first attempt that may resolve your issue. We always recommend checking your Network Bandwith in the Battle.net App Settings, as well as these common steps for Installation and Patching issues.
If the issue persists and it’s during peak internet usage times (such as 6pm-12am in many regions globally), we recommend leaving the download running. As overall internet congestion returns to normal throughout the night, providers are allocating more bandwidth for large file downloads which will improve your download speeds.
now correct me if im wrong but you have made our download speed so slow that we have to wait days to download 20+GB of data @ 20 KBPS YES THATS KB, and the post the above saying we should reinstall the game or change this and that is simply FALSE. YOU are the ones deprioritising our download speed, so a reinstall wont do anything or any other crazy suggestion you have had is irrelevant if it is YOU who have made the download speed slow on purpose. all i have had is problems with this game, crashing to desktop with no error messages, hackers, no support from any of your platforms, you lot should be wearing balaclavas how you rob people of their money, and not even fix what is wrong with the game especially when it is something as easy as turning up our download speed so we can at least attempt to play the game we payed £60 for. you should be taken to court because if i sold something and it did not work, and ignored the people i sold it to, i would be taken to court.