Sorry it didn't work out, but you bought a very light duty homeowner grade product and probably got better service than if you spent the same amount for a lesser brand, off the shelf at a big box store.. This is no different that a few decades ago, when you could spend $4995 for a Yugo, and own a crap pile that needs constant repairs, or twice as much on a Camry, that's still running today. Stihl makes great products that last for years of daily service in the hands of professional loggers, tree trimmers, etc. but they are $400 on up, not $170 like the one you bought. My three series Stihl saw was twenty five years old, and trouble free, when I gave to a buddy in the tree business. He told me he would leave it in the shop for parts. Instead he threw it in one of his trucks and used it regularly for a few more years.
I totally get where you are coming from though. I have to tear a three year old leaf blower apart, to get it running again. I could of ( and regret not) dropped $250 for a Stihl unit, but I grabbed a dirt cheap Hitachi on ebay for $90 bucks. It gave me three years of trouble free service, but it's a light duty unit, and I got what I paid for.