Windshield wiper problem

[HIGHWAY BY THE SEA]

I got my 81 Chevy Stepside back from the painter and the windshield wiper arms were not attached. I took them and got new wiper blades then attached them back to their proper places. But the first time that I tried to turn them on they both went down and slammed/stuck against my shroud near the windshield scratching up my new paint job. They stuck there and I had to bend those things to get them to go back. Thinking they may have been put on wrong I put them back on again, this time with a higher angle, but when I turned on the windshield wiper switch again the same thing happened. What in the world would cause this?