I don't think we have to trade in our tickets, being general, but the concert has been moved from March 20th at Estadio River to the 22nd at Estadio Velez.
Info: http://www.ticketek.com.ar/Conciertos/Rock-Internacional/GUNS-N-ROSES__GUNSNROSES
Info: http://www.ticketek.com.ar/Conciertos/Rock-Internacional/GUNS-N-ROSES__GUNSNROSES