Question

I purchase dolphin 7.0.1 a few months ago and I wantted to know how can i retrieve that download again ... please advise

What you purchased was a license. Not Dolphin which is free. As the licenses work with any version of dolphin, you should be using at least the latest stable version which is 7.0.9

However if you insist on running a version that old containing hundreds of bugs that have since been fixed, then you can find all of the old versions here. http://sourceforge.net/projects/boonex-dolphin/files/Dolphin/7.0/