Is AT&T trying to cheat its customers?

I placed an order for Uverse Elite Internet package and Uverse voice 200. My order # is ***** and my account# is ***** . WHAT I AGREED UPON IS $40/MO. NO INSTALLATION FEE. FIBER INTERNET WIT NO LIMIT. HOME PHONE INCLUDED. One time activation charge of $99 and the also the monthly High speed equipment charge of $7 were waived. I scheduled the installation for 6/21 between 11 am-1 pm. Everything seemd fine until I received a message from AT&T at 10.52 am on 6/21 (several minutes before the scheduled installation) about the change of my installation date to 6/22. I logged onto my account and found out that my order number ( the new one is 2759219088) and agreement were both changed. It was showing that I have to pay $50/mo. (including $10/mo equipment fee) and also the installation fee of $99. I started to chat with a rep. named Karl who could retrieve my original  agreement after some effort. After that he transferred me to a sales rep named Ricardo N. However, Ricardo magically could not retrieve information about my original agreement and kept saying my order was6 Mbps Elite High Speed for $20.00 with a $99.00 activation fee plus the $10.00 for the Equipment fee and AT&T Uverse Voice 200 of $20.00 . We could not resolve the issue and I called the customer service, this did not change a thing. I had to cancel my order. What I cannot understand is how an agreement can vanish after it is being agreed upon by both sides. I have the on-line chat with Karl and Ricardo printed out. In this chat Karl confirmed my original agreement. But suddenly nobody could find it. It just disappeared. I began to question the trustworthiness of the agreements with AT&T. If I had not checked my account the service would start tomorrow after installation and I would be billed for both the nstallation fee and the extra monthly payment probably after 1-month. Is this cheating people or what?

[edited for privacy-please do not post personal or unique information such as but not limited to full names, employee ID numbers, email addresses, phone numbers, account numbers, etc.]