The way not to treat a lifetime customer

Been a Clicks Gold Card Member (card number ***9 16 )registered in January 1997, find it impossible to register for online purchasing as the card is recognized for login but i do not know what my 1997 login credentials are, The registered email address is obsolete and after phoning clicks help line Twice and reviewing details which clicks confirmed as updated, STILL cannot login, will not recognize "updated" email address ....poor performance.