Why won't the goldfish die...?

I have mixed feelings about these goldfish. On one hand they are helpless little goldfish, on the other hand they are JUST goldfish. it started with "fair fish" (the fish Cade won at the fair). When we went to Petsmart to get a small tank for this fish, Cade decided the fish needed "friends". Being the ever pleasing mom that I am, I agreed. Of course I was thinking on a theraputic level, Cade has sensory issues so a fish tank next to his bed would calm him and help him sleep (that's what I'm telling myself anyway). So we take our 2 gallon "self suffiecient" tank, a turtle statue for them to "swim through", some chemicals, food and 2 more goldfish home. An hour or so later Swimmy, Mermaidman and Barnacle Boy Fred (he has 2 names) were home sweet home in their pretty crystal clear tank. The fish guy at Petsmart told me I'd just have to change half the water once a week and the entire tank once a month. For the record, fish guy was an idiot. I let this go on for a couple weeks. I called Petsmart only to get another fish person who doesn't understand how small a 2 gallon tank is. She tells me to get a gravel vaccum. BAD IDEA. That made things so much worse. So my best friends brother is all-knowing when it comes to fish, of course I text him. After a very long texting conversation, it was decided-let the goldfish go in a pond or let them die and then get a Beta. Much easier to take care of. That was a few weeks ago. We've gone away for the weekend twice. They didn't get fed the entire time we were gone. When we are home I can't bear not to feed them, that's inhumane. I guess letting them go in a pond would be fine but where will I find a pond? Will teeny tiny goldfish survive in a real pond? Does it matter since I want them to go ahead and die anyway? and most importantly how did we get the 3 goldfish that won't die? If we wanted them to be lifelong pets they would have floated weeks ago!! Now I must go clean the fish tank.