So you washed a pen in the laundry and put it in the dryer. The ink set in. Oh no! Here's what I did to this shirt I had for 3 years with the ugliest ink stain on it. I bought nail polish remover from CVS, and I dabbed the stain. Don't use the same cotton ball/paper towel.
Keep changing it as you notice the ink coming out. Make sure you test it in an inconspicuous area so your clothes don't stain, like with bleach and other cleaners.