What should a student do if he or she is unhappy with a grade? 

Should a student consider that s/he may have been assigned an incorrect grade, a clear procedure is provided for in the Academic Regulations.  The student may request a  recheck of the grade within two weeks of the relevant semester results becoming available. To request a recheck, the student must complete the appropriate form (available by contacting the Student Academic Administration Office by email - saa@ul.ie ) and pay a fee.
After receiving the appropriate form, the relevant  academic staff member will then (and only then)  review the script for accuracy. The recheck request form will be returned to Student Academic Administration Office with the decision noted on it (including any change of grade). It should be noted that, should the grade recheck so determine, grades may be changed to lower or higher grades.
You are required to follow this process.  
Should a student not be satisfied with the outcome of the grade recheck, s/he may appeal the matter to the Head of Department responsible for the module. The appeal must be made within two weeks of the publication of the grade recheck result. To appeal a grade recheck, the student must complete the appropriate form (available by contacting the Student Academic Administration Office by email- saa@ul.ie ) and pay a fee. The appeal must be on stated grounds and should include a full and complete statement on why the student believes the grade awarded is incorrect. It should be noted that, should the grade appeal so determine, grades may be changed to lower or higher grades.
You are required to follow this process.