You were not a high risk when you opened the account. Probably only a moderate risk (young, little credit history, etc.)
But then you proceeded to charge high balances and pay them close to the due date. That is high risk behavior.
I was a victim of credit fraud and what the person did was take my SS number and a variation on my name and opened up a dozen or so accounts and charged about $50k over about 6 months. Made payments during those first few months and then stopped. This is how a lot of fraudulent behavior manifests.
So do not be surprised if this happens to you again. If you move all your primary purchasing to a new card, you might want to let them know what your purchasing habits are like beforehand.
You can be frustrated, but your are outside the realm of typical behavior and not how most people build a credit history. $5000/month at 22? And you are frustrated.?. You certainly have a different perspective than I would.
BillJ