Did I get ripped off ? dead battery?

I was not able to start my car and I did not know it was the battery because the alarm keeps going off when I attempt to start it so I walked two blocks down to a auto shop and one of the guys came with a booster and increase the car so it started and I drove into there auto shop and notice once I turn off the car it woudnt start again probaly because I didn't charge it enough. afterward on he used had a machine that he plugged in to the wall and to the car to charge. I waited for about 30 minutes then he said it woudnt charge and the batter is no good. I bought a ac delco battery 35 with six years warranty. Did I get ripped off ? I think I did. This is my brothers car 96 es 300 he had it for about five years and never had one time to jumpstart the car. Let me know what you guys think .

2 days ago
$140 for a startup and substitute battery AC delco six years ? I am in NYC and my friends is telling me I got ripped off

Batteries don't last forever, if the last one was five years old it was about to die, and many times they don't give you much warning, they're good one day and gone the next.
If you don't have any more problems, then you know that it was the battery.
Most car parts places have an electric system tester that can examine the system and tell you for sure if it's the battery or the charging system but from what you describe I think the battery was gone.
Just because the alarm goed off doesnt tell you much, that could take little electricity to work and the battery undoubtedly had a little left but it takes a big amount of electricity to begin the car.

no it was the battery's time to go . battery usually go for five years before substitute

Over five years is old for a battery. One sign that they are bad is when they will not take a charge. You did not get ripped off.

If you got a car with a five year old battery, then it was not a bad investment the average life of a battery down here in Florida, caused by the heat, is only about three years.
The major question I have is have you had any more problems with the car since you replaced the battery?

if it has been warranted for six yrs. take the battery back and gather one yrs. worth of money off it or have them put it towards a new battery.

No, you did not get ripped off. In fact you may want to be happy that you went into an honest shop. Now have you brother pay you for the battery since you said it was his car.