Please, have a look at the attached sample application, which demonstrates an approach by which you can achieve a categorical Y axis chart. A simpler scenario would be setting custom strings for each Y axis label.
Hope this helps.
the Telerik team
Do you want to have your say when we set our development plans? Do you want to know when a feature you care about is added or when a bug fixed? Explore the Telerik Public Issue Tracking
system and vote to affect the priority of the items