You can always ask, and they may agree
Or, going by my experience and that of others, they probably will agree
For my own exam, I was really worried about having an experience of the type you describe. So I asked for two pens instead of one (the attendant agreed)
I had a student whose working style was such that she always used a big chunk of the sheet for every quant question.
In her three attempts, she always asked for two notepads at the start of each section - and that was given too
So go ahead and ask, and try to check the pens before going into the exam room.
Also, have you reported your experience to the GMAC as a test centre irregularity? If not, you should: after all, good working pens are essential.
All the best!
Posted from my mobile device