Yeah it's generally a good idea to do a bit of research when you want someone to basically injure you. I don't know how it is in Australia, but here you need a license to cut people's hair but not stab needles through them, go figure. Well, I think the actual business needs to be health inspected or something, but personnel training? Pshh, how hard could it be???
If a "piercer" ever pulls out a piercing gun, even for earlobes, leave. They cannot be sterilized, and the microscopic blood spray in every piercing can pass along diseases to you. The only way to sterilize anything is using an autoclave - what your dentist/doctors use on their tools. There is literally no way to sterilize at home, you can "sanitize" but it's not the same. Ask your surgeon why he can't just use an alcohol wipe on his scalpel and see if he laughs. (If he doesn't, run). Guns also shatter cartilage, can get jammed (fucking OW), and are extremely inaccurate. Not to mention they use the earring itself to stab the hole, which is basically blunt forcing its way through. A piercing needle is hollow and essentially slices a tiny hole in your ear, kinda like a holepunch on paper versus stabbing a pencil through (the flap of paper hanging there : your flesh!). Also, a professional piercer will be trained in first aid if you faint or jerk away or something, while a mall employee would wring her hands wondering if she'll get fired.
This is a good website if you want to let the fuckup heal and repierce in few months:
http://safepiercing.org/
This isn't directed at anyone, just an opinion:
I believe that with the internet and the explosive popularity of forums, there is no excuse to basically not know something. Want a good dog food? There's a forum for that. Want to go skiing? There's a forum for that. I lurked a piercing forum for a weekend and walked out knowing what to look for in a piercer. If you're lazy, post a thread "I want my ears pierced, tell me about it" and let the information flow in.
P.S. You don't need to buy any sprays. Table (or sea) salt and warm water (google "sea salt soaks"), and a dye-less, frangrance free soap will do it all.