Many moons ago a friend asked for financial help. He had made minimum payments on a credit card for a year, but the principal was only reduced by $30 USD when he paid $400. I explained the principal part of the payment was $2.50/month, and that it was going to take 38 years to pay off the card while costing over $10 k in interest. This was before CC reform.
He had never been taught anything about how loans are structured, and I had to explain twice. He was young and inexperienced, but not stupid. He got a second job and put every penny into retiring all his debts, as he was in a financial hole and didn't realize it. A year later, he was debt free and still is today.
It can be done, if the person is motivated.