If your receipt clearly shows Microbiology and the change was done last week, that's actually a good sign—the request was submitted. If the JAMB portal is showing no course at all, it is often a portal synchronization issue rather than a sign that the change failed. I suggest you: Check your JAMB profile again using a different browser or device if possible. Check JAMB CAPS as well. Return to the CBT centre with your receipt and ask them to verify the status on the JAMB system. If the CBT centre confirms the change was successful, keep the receipt safe and continue monitoring the portal. Since your receipt already shows Microbiology, I would not assume you've lost your application. The next step is to verify the status with the CBT centre or a JAMB office. One more question: when you open your JAMB profile, does it show "Course: Not Available/Blank", or does the entire admission details section fail to load