According to several reports, some users are claiming that they have been permanently banned from using WhatsApp. This is following repeated warnings and bans from WhatsApp telling them to stop using third-party clients, to which they defied those warnings thus leading to the permanent ban. Once this happens, it seems that you’d basically have to create a new account with a new number which sounds highly inconvenient.
OsmDroid who is the developer behind the WhatsApp+ client is said to be working on a feature that could potentially bypass the ban, but in the meantime has urged users to return to the official WhatsApp client, at least until his feature has been tested out properly. In the meantime WhatsApp has yet to comment on the perma-bans of its users and if there might be any possible way for them to reverse their decision.
In the meantime if you’re using a third-party client to access WhatsApp, we guess you should probably return to using the official client lest you find yourself permanently banned from using their services.