Equifax lists my credit as poor, yet Chase just doubled my credit line. I am well within bounds of good usage, what can I do to get them to correct this?

Equifax is a credit reporting agency, when you get things like "usage reports" and "credit scores," even if they are from Equifax, they are subjective. Most banks use either FICO or an internal scoring algorithm to judge credit worthiness. That's why Equifax might tell you your score is 720, but another company might say 710. Take all of these "recommendations" with a grain of salt, it is indeed important to keep your credit utilization low, but there is no magic number that will increase your credit worthiness. Also, remember that it takes up to 60+ days for credit reports to update, so if you just got a credit limit increase, it may not be reflected on your credit report yet.