Sometimes things don’t work the way they should. In the case of reverting your plugin to a previous versions simply head over to the wordpress.org repository where all these fine plugins live and navigate to my plugin.
Once there, you can find a ‘Developers’ tab on the main sections of the plugin. That page has all the previous versions available as a zip file. (screenshots below)
You would simply remove your current version by deleting it from the wp-admin and then download the zip or the version you want and reupload it through the wp-admin.
To save you a few steps, just click this link and be magically located at the correct spot on the internet.
Developers tab looks like this:
And then you should see a list of all the old versions like this. Click the link on the left. The link on the right that says ‘svn’ will take you to the actual files and not a zip file.