When you said “downgraded” you meant your plan was changed without your knowing?

Did you upgrade your phone recently? or there was an 5GB add-on in the past with your plan?

When did you change to the 9gb plan? 

When did you notice the plan downgrade? 

Can you check your self serve to see when your plan was changed? And post a screenshot of PDF e-bill wich showing that you had a 9GB plan (without personal info).

@Markus Gallantis Not sure what you mean, your plan hasn’t been changed since you singed up for it over a year ago.