Merchant's Tire and Auto Centers Excessive Over pricing on parts and labor and not being truthful Alexandria, Virginia

Merchant Tire and Auto Centers store location #354 is approx 3 mins from my office.  My car was shutting off and drove in to Merchant Tire.  Attendants in the bay, came out and asked what my concerns were. Explained that the car was shutting off while driving.  They were very kind and did a check on my engine battery poles and told me that the battery charge was low.  They advised me to go and get a ticket written up by the manager on site.
 
The manager on site told me he checked and that there was no battery for my 2002 Cadillac Seville STS at the location and that he would have to locate the battery as it was specific to the make of the car.  He indicated that because it was close to 8p there were not any places that he might get a battery replacement.  He got on the phone and then informed me that a replacement battery would cost an estimate of #350 with labor as the price on the battery was around $250.
 
I googled on my iphone and located Auto Zone and they had the replacement battery in stock for $144.  The manager onsite also informed me that the alternator may need to be replaced and could not give me an estimate but that the cost would be over $700.
 
I went to the nearest Auto Zone and purchased a battery and returned to the shop at 8:45p.  The manager stated that he would have my vehicle ready in the morning.  I told him to install the battery as I had no other means of transportation.  He very reluctantly told the attendant to install my battery.
 
The battery was installed and the car did not seem to keep charged.  The manager told me that I would definitely need an alternator and since it was already 9p closing time, I would need to call the following morning and speak with the Service manager, German Alfaro.
 
I was contacted on Tuesday, March 6 by the service manager, Mr. Alfaro and he stated that I needed to replace the alternator and the total cost was $975.  I had already gotten quotes for alternators and it ranged from $100 to $144.
 
I immediately advised that I will have the car towed.  Around 430 I went to the shop to settle my balance and was told that the car would not start and that I was to pay $73.00 for the diagnostics test and the install of my own battery.  I asked the attendant to let me have the ignition key and went to the car and started the engine.  The car started immediately and I allowed it to idle.  I was then able to drive to my office and will take the car to Tires Plus in Rockville for service.
 
The manager Mr Alfaro never came and acknowledged what was the reason for stating that the car won't start.  I also had to request that they put the old battery in the car so that I could return to Auto Zone and get a refund. The service at Merchants Tire and Auto Center was very unethical and certainly would have cost me much more than reasonable and justifiable costs, if I didn't do my research.
 
Please let the managers at locations know that customers are very research saavy and they will lose business by making up and overcharging for services.   I will post this as an internet consumer complaint