How do I change my credit card details

[mytniva]

I am trying to change my credit card details but can't find how, the screen I looked at seemed to be for sellers 

[robboscoke]

Clear all cookies, history, and cached data. Log out.

Then turn off power for the computer and router and NBN equipment at the wall.

After 5 minutes reboot. Then log on. Do not use Internet Explorer switch to Microsoft EDGE that comes with Windows 10.

[davidenterprise]

Trying to change my credit card details but screen keeps saying "can not process at this stage try again later".

Please help.