Having submitted a survey response, a user received updated information and wishes to update their response.

It appears that this is not (directly) possible. Instead, the user needs to email the team running the survey and describe the desired changes.

There are (at least) three problems with this:

1. It creates additional work for both the person requesting the change and the people organising the survey.
2. It also doesn't scale well, as it places additional load on the team running the survey that is (roughly) proportional to the number of people submitting responses.
3. It is error prone because the submitter must describe the desired changes (assuming they remember the structure of the survey) and the team running the survey then need to translate the written instructions into actual changes to that persons response. Any of these steps could introduce errors in the response.