iPhone 5c question

i have a iPhone 5c without service and alcatel touch evolve 2 from walmart family mobile. Is it possible for me to use my service on my iPhone 5c? A Walmart employee said it would cost me $30 to unlock it, but I don't know where I would do that or if it would even work. someone please let me know, my iPhone is pretty much just collecting dust at this point and I'd love to be able to use it again