It seems the only way is to PAC as much as possible to another providers and close the entire group (well 'close' = 'stop paying'.. smarty don't actually have a close option, not even support can do it).They don't even support transferring to another...
Did you ever get that sorted? I've got the same problem.. faced with cancelling 3 SIMs and losing the phone numbers because of this stupid group stuff. 'Support' are completely useless and just keep quoting google results at me.
