Shell Rewards Company. review: Credit card.

First, I am elderly and suffer from anxiety. I ran up a small purchases, adding up o under $20. Before I linked to one of my credit card. I wrote Shell rewards 20x with the same form letter coming back. Now today I called them most of my day with dropped calls from them. Finely, gave my other credit card and the person said it cannot be used at this time and just hung up. I am literally shaking. My quest is not finished as I want to call Corporate and tell the world do not be deceived and the bad treatment I received. If they send a bill, I will relax. Anyone else received his treatment, I email, and they send a form letter saying they will respond in 3 to five days, All lies. My bills are always on auto-pay. If they send a bill I will pay and if not