GotPrint Bait-and-switch sale of business cards. Offered 500 delivered 100. Burbank California

Bait-and-switch sale of business cards. Offered 500 delivered 100.
Order Number: US-GP-100-22175967 
Create Time: Sep 7, 2017 3:31:26 PM PDT
On Sep 7, 2017 I saw an ad from GotPrint offering 500 business cards for $8. I clicked on the ad, which took me to the ordering page with more information. I followed all the steps and ordered the cards and paid the shipping required. Yesterday (9/20/17) I received the 100 cards. So, I contacted the company asking when they would be sending me the remaining 400 cards, They replied that I ordered 100 cards. I explained to them that their ad took me to a page where I made the order as requested and asked them to send me the missing 400 cards. They said they wouldn't. And offered $5 coupon credit, to which I replied it wasn't an acceptable deal as per their ad. Then they offered to refund the order if I ship back to them the cards. The issue is that they will not pay for the shipment back, which costs $9.44. So, I feel that this was certainly a bait-and-switch ad, in which, one thing is offered and another is delivered. I went back and walk through their system and if you don't know that you have to choose the 500 cards on their system even after clicking on the ad that clearly stated 500 cards, their obscured card count is defaulted at 100. This is clearly not a mistake. It is clearly created this way by default.
I paid for this order with my visa and besides my disappointment with this company's behavior, this ad seems to be a clearly designed to misrepresent their offer and it is deceitful.