Part of roleplaying is playing your negative qualities. If you are in debt, chances are you are in debt for a reason. You gamble, have a huge family, etc, etc. So when money comes in, chances are all you can afford is the interest, because you blew the rest on lifestyle, gear, etc. The only way to be able to pay off the principle is to pay the karma. Think about it this way: if your character had such great impulse control that he could live the low life while sending thousands of nuyen to someone else, would he be in this mess to begin with? The mob (or whoever else you owe the money to) is happy to collect interest every month till the end of time.
Of course there are ways to get out early. You could pick up quadriplegic after you don't pay and the mob breaks your back. There are all kinds of nasty things to replace the points. Heck, you could even pay them off in such a fashion (since they'll take it after they rough you up).
In short, most negative qualities aren't expected to go away over any short period of time. They are part of what makes the characters interesting and provide potential plot hooks to GM's. Try to change your focus off of eliminating qualities and onto playing them up.
