I bought an AWS reserved instance last week and I saw it on the Reserved Instances page on the AWS Management Console. Now, I can't find it! At all! It's like I never bought it. The only 'proof' that I bought it can be seen on the accounts activity page, showing my payment for the instance (medium type instance BTW). What's even more annoying is that I cannot contact AWS for help except I buy a support package. I'd hate to pay for support to fix an error I think they caused. Not sure what to do now.
a reserved instance is just a billing term. If you have a medium instance running it will pick a medium instance to use for the billing terms.
If there are no medium instances running that it might have been retired. That happens if you don't pay attention to your email. Sometimes with ec2 is the hardware suffers a failure so they retire everyone's ec2 instances on that hardware. They send out an email with a retire date. Another thing is the hardware might have just died quickly so no warning email was sent out and it's now just gone.