If you've used and maintained it as per their instructions then they should
replace it. This is from their website.
Care & Maintenance: For best results, always keep your GO! cutter clean
and lint free. To clean the cutter inside and out, use a soft dry cloth. Avoid
abrasives, solvents and spray cleaners. If necessary, wipe with a damp
cloth, then polish with a dry cloth. Use canned air to clear lint from roller
area. The GO! fabric cutter does not have replacement parts.
Limited One-Year Warranty: We promise your personal AccuQuilt GO!
cutter will be free from defects in material or workmanship when used as
directed. If you experience a manufacturing defect within one year after
purchase, AccuQuilt will repair or replace the cutter at no charge.
Improper use, excessive wear and tear caused by commercial use and/or
damage caused by the user will void the warranty. This warranty covers
only the cutting unit--not mats or dies. To receive a replacement unit,
return the cutter to the place you purchased it.