How do I make a complaint about an AT&T retail store employee and the store manager

My 85 year old father visited a retail store a few weeks ago and asked for a phone for himself and my 84 year old mother along with a simple plan.  He later told me he was getting two phones and service.  I asked him where are the phones?  He said he was told he would have to wait until they arrived at the store.  Two days later one phone arrived.  I visited the store with my father to activate the phone.  I asked for his plan details.  Employee told me he could not print any information until a bill was generated.   I questioned and thought this is very odd.  We were told we needed to come back once the other ordered phone arrived. 

Later that day we visited a corporate store to purchase a screen protector and the employee there printed the order summary for my father.  Reviewing the order summary was shocking.  The retail store had ordered 5 phones with 5 lines for my 85 year old father.  He also set him up for paperless billing and auto-pay.  Days later I verified that they had a bogus email for my father.  I spent 5 days and many hours on the phone with the loyalty department.  I complained to the retail store manager once I discovered my father had been set up with an installment plan for 5 devices and 5 lines.  My father was never told he was getting 5 devices.  I was told by the retail store employee that, "you don't understand AT&T plans" 

I'm very disappointed with this treatment of an elderly person.  He walked in with an old flip phone active with another carrier.  He only wanted a phone for his wife and himself.  He wanted a basic plan.  

The Loyalty department has been very helpful.  They have since deactivated the 4 lines not needed.  We decided to wait on activating a phone for my mother with this mess unresolved.  He has not received his first bill to date. 

I believe there should be a review of this situation and our interaction with this store.  How do I preceed?