How do I check refund status of my Apple Gift Card using Case ID?

Bought two £50 gift cards from Morrisons and both of them had their codes torn off of the card, so we tried to refund them at the counter only to find that the only way to get a refund for them would be to contact Apple directly. We have been given a case ID for the refund inquiry but are not sure if there is way to get updated on what is happening with it as we have been having a lot of trouble using and navigating the support site. Any advice would be appreciated as we are owed £100 for the two invalid gift cards.

[Re-Titled by Moderator]