Alarm clock RCL RP 5420 C troubleshooting

The modern alarm clock is more and more complicated stuff compare to the old stile mechanical alarm clocks. The problem is that the functions of the buttons can not be understood easily and sometimes the combination of buttons should be pressed to make the right change. So on my alarm clock the alarm was activated and it worked but I can not switch it off. I can nap it but next day it will sound again and very loud at the end. The description does not help, looks like the function of switching off alarm does not work. The solution was to restart the alarm clock - I unpluged it and deleted the battery. Now, at the new set, the  alarm does not turned on and unless \I  erroneously turn it on, it will be silent.