Depending on why your claim was rejected, you may be able to submit another EC with more information, evidence, or a clarification of what happened.
If the University won't change the decision, you may have grounds for an appeal. Please note, you can't appeal against the EC decision itself, but you can appeal against your module results when they are released. Once results are released you have 10 days to submit your appeal.
On the appeal form, you will be asked whether you submitted an EC and, if you did, why it wasn't accepted. Include as much detail as possible when explaining what happened with your claim - look at the reason for the rejection and think about whether the decision-maker misunderstood your case, made an unreasonable decision, or if you hadn't provided enough detail or evidence.