As mentioned above, I have checked your account and found a subscription pf Adobe PDF Pack which is an online service and that you can can use with the desktop application Adobe Reader DC (free application).
Would you let us know what upgrade you are looking for? Were you trying to upgrade to the Adobe Acrobat DC?
Hope you have tried the steps mentioned in Upgrade or change your Creative Cloud plan
If that didn't work, then you may contact to-support our billing team would go ahead and help you updating the plan.
Hope this helps.