AT&T doesn’t honor online promos

I signed up for AT&T internet as a new customer. They are running a promo for their 1000 mbps plan for $70 a month for new customers till 6/9/2019, which I signed up for.  I checked my account info a couple of days after and it showed I was enrolled in the 50 mbps plan instead.  AT&T customer service was called and they put me on my requested plan but told me to call back so my online promo could be honored. I called back a week later and was informed this promo does not exist and they only give me $10 discount off of $100.  They had $80 for the 1000 mbps plan but you have to bundle it.  Online the bundle is $60.00 for 1000 internet. The customer service rep escalated it to corporate.  I am now stuck with 100 mbps for $60.00 until I hear from them, assuming they honor their promo. AT&T does not honor their online promotions and will bait, switch and screw their customers and not allow customer service to fix this. Is this even legal? I wish I could go somewhere else for internet but this is the only internet provider in my area.  

I also have a screenshot of this deal as proof but I can’t add it due to photos saved to an iPhone not being supported on this website. Go figure.