Switched from a 2-wire to a 1-wire connection

So, I've been having a great deal of trouble with line 2 of my bonded pair.  Five or six techs later, they switched me to a single wire.  I have been paying for 50 MGBS service and now discover that many of my devices don't have the proper wireless card to get 50 MGBS.  So now I have a 2.4 ghz and a 5.0 ghz connection.  But I can only get the 5.0 ghz on my iPad.  I was never informed of hardware requirements when I signed up for 50 MGBS service.  I feel that AT&T would rather take my money than provide me with full disclosure.  Why wasn't informed of this when they came to replace my modem?  I am considering several approaches to this, because AT&T has been taking my money for service it is mostly impossible to have.  So, AT&T, the ball is in your court.  Between my business and my home, I pay you over $1900.00 a month.  You can fix my service, or you can lose both my home and my 7 office landlines and my 7 cellphones.  I OWN A BUSINESS.  WHEN YOU TREAT PEOPLE LIKE THIS, YOU LOSE MONEY.  I will be sure to contact everyone on my neighborhood box.  You aren't going to lose just my business due to your deceptive business practices.  

@ATTDSLCare

@ATTHelpForums