INSTYLERS Are A Scam would not refund full credit after returning product Internet

After inquiring information about the product Instyler, I was called at least 10 different times from a customer sales rep. with offers to purchase the Instyler product.  The last offer included a huge discounted price, along with FREE shipping/handling, and an upgrade to the salon model Instyler, Rapid Heat Up for only $115.96 (originally $139.92 + $19.99 s/h). I was getting this product for a discounted price of $23.96 plus FREE s/h for a total savings of $43.95.  I opted for the insurance for an additional $9.95, totaling a one time charge $125.91.

The first Instyler I used was defective.  The barrel would not spin unless I squeezed really hard, causing the metal to grind together.  I called to return the product but the customer service rep. was really nice and offered me a $15.99 credit refund and free hair products if I just tried the 2nd Instyler.  So I tried the 2nd Instyler.  It worked only it would not straighten my daughter's hair.  It worked as a great curling iron on my hair, but that's about it.  So, I called to return it a 2nd time.  The customer rep. was really persistent on getting me to keep the Instyler and offered another $15.00 credit refund if I would try it with the "free hair products", which I had not received yet.  I never received the 2nd $15.00 credit and the Instyler still did not work, even with the products. 

Finally, I called a 3rd time, and the customer rep. gave me a Credit Return Authorization Number so that I could return the product for a refund.  I paid $13.65 in postage fees to return the Instyler.

I really believe they were trying to make me keep the product past 30 days so I could not return it.

Okay..here's the problem: I was credited back a refund, minus a $19.99 shipping/handling fee that I was not supposed to be charged for initially.  I called customer service and he explained that I was "charged a shipping fee" in my order and there was nothing I could do about it.  I spoke with 2 different managers, who basically said that I was lying about the "FREE" shipping offer because they do not offer that type of discount. 

The customer sales rep. that sold me the Instyler supposedly recorded the sale because he asked for my permission to be recorded.  I asked the first manager to review the tape/message from the sale and he rudely refused and said  "I'm not giving you a refund and I will not review the tape."  I called back and spoke to another manager and she said that she was not authorized to credit back a shipping fee and that there was no way to trace the record of the sale or even who made the sale but did offer a customer service complaint address--without a telephone number!! 

I guess people will say anything to make a sale.  I know what was offered to me and either the customer rep. lied about the FREE s/h fees or the company is covering up his mistake.  Either way, I should not be penalized for their mistakes.