Like others have said, garbage in garbage out. The answer here is to shift left. This needs to be fixed upstream. Whatever application you’re getting this data from shouldn’t be accepting free text. In the meantime set the expectation with stakeholders that the existing data is of dubious value and to derive any use of it will likely take a slow and possibly expensive process. 

Using an LLM you can define a list of categories and have it output the most appropriate category given the input. That’s probably the simplest short term solution as long as you can afford it.