Are you saying that your name has been altered without any intervention on your behalf.? If originally your username was 'poorclare', how did you know it had been altered to 'poortony' and then back again to 'poorclare'.? I suppose it is possible, if like myself you do Not log-out from AB, that you could be welcomed back under a different name because there would be No need to sign in with a password.
It would be interesting to have an explanation for the events; if anyone is able to comprehend what could have happened.
Al.