Tune up, oil change, inspect the suspension

Took my car in for general maintenance, check engine light was on- it was never on before... car broke down less than 10 minutes after it was picked up. Made them tow it back to see what it was, they left a hose detached. Said not to worry about the light, it happens and is probably just a code. The headlight blew out of nowhere. Noticed a oil burning smell, oil was on my alternator. Took it to auto zone to be tested. They noticed the intake manifold was placed completely wrong, that caused the check engine light and now I have a valve gasket leak. That was the burning oil smell. Ow my car is in worst shape and am having to come out more money. Imagine if I'd trusted the mechanic and really went back to him like he expected.