Radio code - i cant figure it out!! PLEASE HELP!!!?

took my car to the garage yesterday n they had to take battery out to fix a different problem n they didnt bother puttin the radio code bak in the st*pid idi*ts!!
all day i have been ringin them up 4 the radio code n i have finally got a code

they have told me how to put it in...

turn engine on
hold AS button down
turn radio on
wait 4 the beep
enter the code
press AS again wait 4 another beep

but when i hold in the AS button 4 the 1st time it never beeps!!

does anybody no what to do?? i dont want to take it bak to the garage as im sick to death of the people there!! SO THICK!

pleaseee help me