Hi Mauvega,
If all above solution does not work then you have to pass manual JV to both account i.e. (Correct a/c) Client A and (Incorrect) Client B.
I think if you tried to reset & revrse that clearing document then system won't allow in cased of all three invoice partially cleared against one document,
In case of any issue, please let me know.
Regards,
Dattatraya B.