Harbor Freight Tools

Bought a generator from Harbor Freight on a Friday evening tried to return it Saturday morning because it was to heavy for me to get out of my trunk. Was told 20% restocking fee even if was never open or remove from my vehicle. Was told by store manager their policy was on my receipt. When I mention you don't received a receipt until you purchase product. She shrugged her shoulders. I called the 800 customer service number when I got home. Received a email stating area manager would contact me within 3-5 business days. Still have the generator in my vehicle no call from manager going on 7 business days. Do I return generator for $90 fee as they take it out of my trunk and put it directly back on their shelf for sale?