When you push the wiper switch down on my 200tdi, for intermitant, you get slow. When you push it up (from off) you also get slow. When you push it up to the top, you get very fast. In any of the positions, when you turn them off they dont reset.

Do I need a new switch stalk, new wiper motor or is it something wrong with the wiring?

for the wipers to park, the motor need a 12v ignition feed to the park switch on the motor, if there is no feed or the park switch is nakered then the wipers wont park

check for a 12v feed to the motor when the ignition is on but wipers off, if you have the feed, check the earth, if thats ok then its a motor fault