The chain probably had a double-loop in opposite directions that got pulled tight. No big deal, you dad figured it out. Thing is shops shouldn't even bother with repair-jobs like that. In my shop, I would've just straightened it out by hand for free and sent you on your way. Wasting time is what makes an operation inefficient and I would've spent more time giving you estimates on that repair-job and haggling over the price than it wouldn't take me to fix it, so I'll just do it for free and be done with it.

And haggling is perfecty fine. The most expensive items most people will spend their money on, houses and cars, should definitely be negotiated. However, most people have no practice and absolutely zero skill in haggling over prices. Better to practice that on small items and learn the skill before you get taken with the big ticket items. Most people going in to buy a car is dealing with a professional that does this every single day of their live. How are you even gonna stand a chance?

In many cultures, haggling is the norm, and if you don't haggle over the price of a mango, you're gonna insult them. The implied message is, "I'm too good to deal with you.". Most places in Asia, middle-East, S.America, Central America do not have price tags on things. You have to ask them and start the negotiations. The 1st price they tell you is about 2-3x higher than what they're willing to sell the stuff for. If you just take it at first value, you're over paying and they're more than willing to sell it to you at that price.