I've downloaded the starcraft game client from the website but why can't I install?

I've downloaded the mac version of the game but for some reason I cannot install it. Every time I run the installer it asks for me to insert the disk which I do not have, and I just went through 4 hours to download a 6.99 gb file which im pretty sure is what is on the disk. I know my macbook pro can run this game. Also the files that were downloaded were Installer, Installer TOME 1.MPQE, Installer UI 1.MPQ, and Installer UI 2. MPQ. The Installer tome 1 MPQE is 6.99 gb.