Can I force my company to pay back pay?

I work for a security company in NC. I am contracted out to a customer. For two years I asked for a pay raise. The customer approved a pay raise and has been paying my security company the requested pay raise since April of this year. My company is beating around the bush and has yet to give me my requested raise. They keep saying it's coming but as of today I have yet to receive my raise. Can this company be forced to back pay me to April if and when I receive my raise?