I purchased 2 games but the wrong system. Can I convert them or do I have to buy new games under MAC IOS?

Games bought on GOG can be played on any of the supported systems, and any given game can support one or multiple of Windows, macOS, or Linux - you cannot buy for only one system, you get the game for all the systems it supports.

iOS (as in the OS running on iPhone, iPod Touch, and iPad - those are not the same as the Mac) and Android are not supported by any game on GOG.

Not all games on GOG have releases for macOS or Linux. If the games yo bought have a macOS release, you already have it, if they don't , you're out of luck (you can try asking for a refund if you haven't already downloaded anything).

.

As a side note, and completely unrelated to your problem, I feel dirty typing "macOS". It's "OS X", dammit Apple! Stop trying confusing people into thinking it's in any way related to Mac OS.

What games?

You don't buy separate games for separate OSes here. If the game you bought is available for Mac, then just choose the correct OS when downloading. See attachment.

The more i look it appears the games i bought, Railroad Tycoon and Civilization are windows based. It was rather confuing when i chose them because I queried IOS games

Are you looking for games for the iPad/iPhone, or for the Mac? The Mac runs macOS/OS X, and the iPad/iPhone runs iOS. GOG do not sell games for the iPhone or iPad.

How did you query it?

To filter by Mac games, select OSX under System. Or use this link.
https://www.gog.com/games?system=osx_106,osx_107&sort=popularity&page=1

To make sure once you select the game, check the supported operating system on the right side of the game page.

Anyway, contact Support using this form here, and if you explain the situation, they'll probably give you a refund (definitely if you haven't downloaded the game).
https://support.gog.com/hc/en-us/requests/new

EDIT:
Also, what Maighstir said^.

Also, if you are downloading the games eg for a Mac on a Windows computer, you must make sure to change the system setting in the game card or it will automatically assume you want it for the OS you are on currently.

Thanks costly lesson learned. Thanks for the help. Much appreciated

No, no extra charge. You are allowed to download it on several different OSs if you so like. I have some games I play on both Windows and Linux so have downloaded those two versions without paying any more. It is only me playing the games anyway, noone else here.

Of course, if you have to pay for internet by the minute or by the GB, then it might have cost you.

Thanks, unfortunately he games I purchased are Windows only.

ah :-(

Wine to the rescue!

https://www.gog.com/forum/general/the_judas_does_this_run_in_wine_thread_v1173

or as I said, Support should give you a refund. Especially if you haven't downloaded them yet.

Thanks

Those two games should work on macOS and iOS.
You just need dosbox or something similar, and a bit tweaks.