I had this card for more than 2 years and like yourself, I only received a $100 increase (never a late payment). Do not expect to receive any more increases. This is a great card for establishing credit, but once you’ve done that you need to move on to better cards. They do not make an effort to keep you as a customer when your credit improves. That’s why I closed my account and applied for better cards elsewhere.
Let me give you a tip. When you decide to close this card and apply for a better one, bring your deposit up to the highest amount you can afford, let the card report your new credit line to the credit bureaus and then apply for a new card (you can then close the CapOne card and get your deposit back). Banks will try to offer you cards with at least the same credit limit you have with other banks. If you have cards in the $500 range, they’ll most likely offer you a card around that same credit limit.