You could buy them online; badges aren't expensive, probably no more than $12 total. Some websites are: www.medalsofamerica.com www.uscav.com www.brgadequartermaster.com To find retailers who may be able to obtain badges for various services, enter the service name followed by the desired insignia into your favorite search engine (e.g., "air force badges").
I don't have a specific answer for you, but they usually are for sale online
Large amounts of magnetic letters can be bought from many stores online. Oriental Trading, for example, sells a 135 piece set of magnetic letters for $16.
Internets
You can purchase Gallagher Girls badges from online marketplaces such as Etsy or eBay. You may also find unofficial replicas available for sale.
On eBay
brand name clothes online
Spa Ladada, Claires, piercing pagota, and that's were you can get them.
You can buy magnetic thinking putty from various online retailers like Amazon, as well as specialty stores that carry a wide range of toys and novelties. Some well-known brands that sell magnetic thinking putty include Crazy Aaron's and Creative Kids.
Car stores such as Halfords usually sell a wide variety of magnetic car stickers. Alternatively, you could find and buy stickers from an online store.
There are 19 lots of 20p in 3.80 So you can buy 9 lots of 3 badges, which makes 19*3 = 57 badges.
You buy them at the poke-mart once you have enough badges