Cash for Laptops Bait and switch offer for used electronics Reno Nevada

I recently bought an iPhone 6.  Both AT&T and Gazelle offered me $70 and $86 respectively.  Since my phone was in excellent condition, I decided to go with "Cash for Laptops" online offer of $113.  I received an email a week later that they would pay me $13 for my phone.  I immediately sent a email that this was unacceptable.  Their response was sending me a phone number to speak with a representative.  Getting through was next to impossible- if you are on hold for more than 7 minutes, the system hangs up on you.  It took me over a week to reach a person who basically said that there was nothing I could do. They mentioned that my iPhone 4s was now worth even less on the market.  I did receive my check for $13.  If I had used Gazelle or AT&T three weeks ago I would have received at least $70.  BEWARE of this company!  Unbelievable that they can get away with this!!!!