Here is how you can request a refund for your mobile order. Simply visit mcdonalds.com.sg, click on FAQ, select one of the categories, and then click on Contact Us at the bottom of the page.
Step 1- mcdonalds.com.sg
Step 2- FAQ
Step 3 Select one of the categories
Step 4 - Click on Contact Us
Step 5 - Please select Mobile Order under Order Type
Step 6 - Select ( double charge, food not collected, payment issue, etc)
Step 7 - Fill up the form and submit