Advice Needed

Hello, ladies and gents. First time poster here. I need some advice. I'm new to air rifles and was looking for a quiet backyard shooter that is capable of killing squirrels. Damn critters are constantly digging through my garden. I live in a residential area, so it's very important that the rifle needs to be quiet. At first, I was looking at the Umarex Notos, but found out later that my workshop air compressor isn't capable of filling up PCP air rifles. I also didn't want to spend more money buying an air compressor to fill up PCP's, so I decided to check out break barrels. After reading various reviews and watching various videos, I settled on the Gamo Swarm Magnum 10X GEN3i. Some reviews mentioned that the rifle is fairly quiet. The rifle also seemed fairly quiet in some videos. The rifle came in a few days ago and I finally shot the rifle today at my squirrel-feeder that has a backstop, and boy, was it loud as hell. I had to run back inside the house in fear that someone would call the police on me. So, my questions are:

1) I raised a ticket with Gamo. They haven't responded yet. Do you think Gamo would accept a return of the Gamo Swarm Magnum even though I have fired the rifle once? If Gamo doesn't accept the return, what should I do with the rifle? I have zero use for this rifle. It's way too loud. It almost sounded like a real gun. How and where should I sell the rifle?

2) Should I have just gotten an Umarex Notos instead and picked up a hand pump?

Thanks in advance.

Have you considered a multi-pump rifle? Variable power, accurate, easy to fix. A Crosman 362 and some good pellets will resolve your squirrel issue and not break the bank. They have been killin' squirrels forever.

 
Have you considered a multi-pump rifle? Variable power, accurate, easy to fix. A Crosman 362 and some good pellets will resolve your squirrel issue and not break the bank. They have been killin' squirrels forever.

Not break the bank? Sure, assuming you leave it stock. Once you replace the breech, scope it, replace the bolt probe, etc… you’ll have $300+ sunk into it in no time and IMO they’re not really very good guns in stock form. Sure, you can build them into something that will shoot on par with much more expensive guns, but that $120 Crosman 362 isn’t going to equal a Notos in stock form.
 
As mentioned in post 12, you really need to check on the legality of what you’re wanting to do. A hunting license would probably be needed and done in season.
You might be better off discreetly trapping them. I’ve seen these traps that use a 5 gallon pail with a trap door on them and they fall into water. Maybe a garbage can size for squirrels, they are very athletic. Think this through though.
Are there pesticides that discourage squirrels?