Not usable after registering

At first glance the plug-in seems to be able to do most things I want.
But trying it is a bit hard. Altering a few options a few times, to see what happens, and the trial is over.

I thought to have seen enough, so I ordered the paid version. I got the license soon enough, but when I tried to installit I got the error that the plugin could not write the file.
So, I manually checked that the folders are writable.
Still no go.
So, I tried to uninstall it through WordPress itself. Uninstall did not work. Manual uninstall did work. Reinstalled through WordPress, both manual upload and automatic install. Both still had the above problems. Installed manually through FTP, still problems with writing the license and uninstalling the plug-in automaticly.

I contacted the support E-mail. But after two weeks, there is still no reply. So now I have asked a refund through PayPal. I hope the refund will be done.