Job Offer And I'm About Going For NYSC: What Do I Do?

Hello house,
I'm in a fix and I need your advice.
I did my IT (Industrial Training) two years ago in an oil company in Port Harcourt, spent 8 months there. Now I'm a B.Tech graduate, going to serve with 2015 batch A of NYSC.

This evening I read a message from my supervisor (back then at the company) that there's an opening in the office that she's about discussing with the division manager to fill me in. She's aware I'm a graduate now, but she doesn't know of my NYSC status (yet).

The opening is actually by July 2015, of which NYSC camp starts on May 5.

The reason she prefers me is because of my experience with the company, even as an IT student back then. A friend of mine that we did internship together in the company is already working there now, and the pay is well into the six figures arena.

The company, from what I've discovered when I was with them, actually prefers employing people that have worked with them in one capacity or the other before, that's why my friend could easily fill in (with just ND, he's even yet to do his HND). And that's also the reason my supervisor wants me there.

I'd initially decided I won't influence my posting, but even if I do, what are the chances that my PPA will be that company? (I'm quite aware Rivers state corps members are majorly deployed to schools though).

I'm yet to discuss this issue with my supervisor, cos I don't have a perfect explanation yet.

What do you think I can do? Should I just say no? If I do, I stand the chance of entering their 'black book'. This company doesn't enjoy people turning down their offers (From experience), hence, they might not accept you in the future even if you apply for a job telling them you've worked with them before.

Mature and practicable advice please. Thanks in anticipation.