bad customer service

My boyfriend purchased a safe way hairdryer at this store not so long ago, <br> I've been to the store twice as I lost my slip but this manager refuse to assist me without my slip.my dryers still under warranty but they telling me they can't assis me and I know for a fact that they can as another branch of theirs assisted me without a slip not so long ago. The way they deal with their clients is unprofessional. <br> I have to drip dry my hair now as my dryer is broken.