Sad to hear your part of the story, but you wont get a good rate on refinancing unless and then you pay off you credit card delinquent balances. Just cause you pay your car payment on time doesn't make your credit score jump!!! Credit card balances are what hold you score, So my advice is pay the credit card balances ASAP, and then wait a month then go talk to a local credit union!!! If you live around East coast try https://www.itcu.org/ they have good rates on auto refinance.

Hope this helps and good luck with increasing your credit score!!!!