I have mates who spent literally their entire lives in a certain country but still ended up being deported after graduation. Like I said, Canada doesn't owe you anything and this applies to every other country in the world out there.
I wonder why you did not opt for OINP from the start. No, scrap that, why didn't you even check the application that your company submitted for you? If my future is on the line, I would've gone through every nook and cranny, every step of the way. You could've applied for it yourself after a year's worth of work experience in Canada but instead, you put your blame on your company/CIC on a screwed up application. Your credentials, above average as it may seem, holds no value in the face of a worsening economy coupled with an overflowing pool of fresh graduates in the market. That's the unfortunate truth that you need to wake up from.
You're not going to gain any sympathy here. Like yourself, I'm an engineer with top of the line credentials who fought to get to where I am today. I've met a lot of new migrants expecting everything to be laid out to them on a silver platter and ending up working in survival jobs with no end in sight, constantly complaining how this country has been unfair to them when it's not.
Your situation is self-explanatory and I'm sure you're smart enough to figure it out one day. Engineering is a profession with tough competition, but if you do succeed, you'll have a bright future. If your venture in Canada does not succeed this time round, head out and look for career opportunities around the globe. Despite limited opportunities in my home country, I managed to kick start my career with in the locomotive field in the middle east (I'm east Asian), before being headhunted by one of the top three oil and gas companies by revenue a year and a half later. It's been 8 years since then and I've been cross posted all over the globe and finally decided to call it quits when I've gained enough cash to start a new life in Canada with my wife and child. That being said, I ensured my CV stays competitive throughout the years and secured employment, again, with one of the top 3 Canadian oil and gas operators within 2 months of landing in spite of waves of layoffs in the industry.
I was a long time lurker here, and to be honest, I was contemplating my decision to move here as I did not want to make a career out of survival jobs. But after landing, the only over-qualified migrants I've seen working permanently as cashiers are those who are not willing to up their initiative in improving their skillsets. So, yes, competition is tough. If you're competitive enough, you will get your PR, and you will secure employment. If you're the same as the next average Joe, why would a country take you in when they can find better candidates within the country?
In any case, good luck to you and your future endeavours.