Do I have any legal right to fair grading by my university? (UK)
The procedure for complaints and appeals against  the decisions of UK Universities is managed by the Office of the Independent Adjudicator for Higher Education (known as the OIA).
They will only consider your case when you have completed any formal internal processes of the institution and the institution is required to issue you with a &quot;completion of process&quot; letter confirming your complaint or appeal is at an end.
To make a formal complaint or appeal within your institution you will certainly be able to get advice, help, support and representation from the Students Union and their respective Education or Welfare officer. It is highly likely that there are also University staff who can assist students with this process, perhaps called Senior Tutors, or some such title.
Before going to the formal process you should also see if an informal resolution can be made, as is often the case when it is a simple error or system fault. You might need to contact the departmental Director of Studies, Programme Director or Head of Department. You are also likely to have your own &quot;student reps&quot; within your class or programme that also can raise a case for you within the department. They often raise such matters of quality within a framework of a &quot;staff student committee&quot;. The UK Office for students would  likely expect such student representation to be present within a UK institution.
There will  be information about this on the web page of the university and the web pages of your students union or student association.