There really isn't a lot of support for a banned account that can be provided here or on the forums.
With regards to third party clients, Jagex does not endorse the use of any of them and would recommend only the use of the client which is available for download on the Old School RuneScape homepage. Any others are used at the player's own risk.
For more information and answers to any questions that you may have regarding the ban, please see the
Account Bans
support page. Outside of that, there really isn't any further assistance that can be provided via the forums, as offenses are a private matter between yourself and Jagex.