What does this have to do with your question?
you did not get Reforged for free, your classic version of the game was patched/upgraded to the new Bnet client (for free) but you still have to pay for accessing the new Reforged campaign + graphics (its really not that confusing if you take more than 2 minutes to do some reading)
Reforged came out at the end of December or early January (depending on if you played the beta or not), the old Bnet was shutdown around the same time (8 months ago)… and this is the first time you checked out Reforged? thats so strange how you stopped playing just before the release of Reforged and never once bothered to look into this stuff before now??
it is certainly possible to return to the original client on an older patch, but you will not be able to connect to the current Bnet servers using an older patch. Thats basically how it works anytime any game gets a patch, ever. No game that I know of continues running servers for older patches that are no longer being played on.
5 years ago when WC3 was on patch 1.26, you could not login to Bnet on patch 1.24, it just doesnt work that way… and the same is true for the latest version as well
Did you buy Reforged or not? Im confused are you talking about a refund for the original game? lol why would they do that… if you did NOT purchase Reforged, then how can you ask for a refund when you still want to play the game? Seems a little hypocritical… you were given access to the current latest patch on the new Bnet servers for free, at least they didnt force you to pay for Reforged just in order to keep playing the classic game…
Man you sure do ask a lot of questions… maybe calm down about all the changes and try doing some research and taking the time to learn and understand somethings for yourself… Im not going to bother going into such minute details when you just turned the game on for the first time, show that you actually care first
theres other things you could be explaining, since you want help, I mean I assume you prefer custom games and not ranked ladder right?? Well if you really are so desperate to play the older version online you can do that with modded servers, but Im not sure you are up for that stuff
Because thats the world we live in. If you still own the original CDs of the legacy edition of WC3 then you can sleep safe at night knowing nobody can ever take that away from you… but there is no guarantees that Blizzard has to owe you a life time subscription to their online gaming services for free forever… thats not how things work in this digital age we live in… if you dont like it well, complaining on the forums doesnt help much 
the map making policies are for several reasons, they cant allow copyrighted material, and they dont want to let another dota happen, you do know the history right?