As a general rule you do not get a settlements with a payment plan...settlements by defination are a one time payment. Some creditors will allow a year of payments. A payment plan usually requires you pay the entire balance including the accuring interest.
Cap One is likely to sue you.
Since you are not dependant on the income, get a JOB and use that income to pay off this debt. So what if they garnish you! The debt is being paid. Employers see garnishment orders every day...they are no big deal.
How to Deal with Illegal Loans..OhioGal's Primer http://www.debtconsolidationcare.com/paydayloan/dealingwith-illegallenders.html SOL for all states http://www.debtconsolidationcare.com/statute-of-limitation.html