running board warehouse real truck.com refuse to accept return despite their return policy

I ordered the wrong part and called them 6 times to try to resolve issue. their return policy says they accept returns with 20% restocking fee. However the service people including the manager "lil" said since I order the part on line without the help of a phone call to one of their sales people they have a no return policy. NO Where on the web site does this info occur and I have read their return policy multiple times. So I am stuck with a 600$ part I can not use. I will never order from them or their other shill company "reALTRUCK.COM"