I keep getting e-mails from Etisalat for a similar amount as well. I closed my account in person, but they kept it active for a few months. When they called me to confirm the cancellation, I was advised that I had to pay a cancellation fee. I had already exceeded the minimum contract period, so I refused to pay any fee. They’ve been threatening with legal action for the last 3 years. I didn’t get arrested when I went back to Dubai, but I have to admit that I was a bit worried when it took longer than usual to check my passport.
Not sure what will happen if they ever take legal action, but so far they didn’t. I think that they are just threatening with legal action, hoping that you’ll pay eventually.