ISBoxer (not ISOBoxer), is not a cause of getting your account banned. It is even used by Blizzard employees.
Bans are also not given out for multiboxing, as Blizzard also have repeatedly said, throughout many years, that multiboxing is OK, and even gone out of their way to defend the playstyle - as well as differentiate what multiboxing is vs botting. THEY EVEN HAVE A
POLICY ON IT. And just for luck,
here's a bunch of quotes, and some
more, and if I could find the video from Jeff Kaplan (VP of Blizzard), where he said he was multiboxing, I'd link that too.
Now, just to get it out of the way, the Policy says:
We do not actively support multiboxing tools.
In other words, if they be broke, and the game don't work with them, don't come to us for help. If you weren't allowed to use such tools, it would say "You cannot use multiboxing tools".
Sometimes however, repeated reports from other players may get you incorrectly suspended. However, as these reports are generally investigated and a GM determines that 1. you don't respond to their PM, and 2. the behaviour looks like you are botting rather than multiboxing, then you can be suspended. You can appeal, and sometimes it takes two or three rounds, but we have it on good measure, these are almost always overturned and your account reinstated, when there is no foul play.
Unfortunately, we can't help you with the process of appeal, only provide a small amount of sympathy.
That all said, if it will make you feel better to get a refund for InnerSpace (ISBoxer is free so there be no refunds given), and you are within the
account policy timeframe, then by all means, please do so.