MEGA don't have specific number of times a file can be downloaded, but have a limit on how many MB you can download per amount of time. I suggest make a free account for MEGA. It should give you bigger limit. I also try to download beforehand to confirm it is not lost/blocked. It work fine
Non-account only have 1 GB Download per 6 hours and if you are used non-account, you will have 4 GB/day.
While Free Account have 3GB/6 hours which is 3x than non-account and you can DL up to 12 GB/day. I suggest you make Registered account just for Free one and Buying their priviliges is just optional if you are not an Host Sites or Server based type