stereo/CD steering wheel quick change arm problem. ???

I had my stereo changed at halfords and they did not wire in the arm next to the steering wheel.
my car is a 306 td 1997 and the stereo is a sony (not sure the model)
do i need some sort of adaptor ?
is a new arm required ?
there is spare ports for cables on the back of the stereo but the wireing from the arm is not compatible.
please help, i'm far to lazy to reach all that way to change song??????????? ;-)