How can i fix the windscreen wiper on my Suzuki Vitara 1.6 JLX Se P reg?

The windscreen wiper blades became stuck in some heavy snow, and since they will only operate in `fast` mode. I have lost intermittent, slow and the self park facility. The Haynes manual shows an intermittent wiper delay, but the Suzukis dealers say there is not one fitted and i cant find anything that looks like possibly one. Could anyone please suggest what the problem is as the cost of taking to a garage would be prohibitively expensive. £100+ alone for the wiper motor.