Nikon 55-200 lens trouble?

I have a nikon d60 with a 18-70 mm lens and a nikon 55-200 mm G f/4-5.6 ED… The set was bought in july 2009… While shooting a football match i met with an accident where i had a head on collision with the ball… My lens was all the way zoomed to 200mm and retracted with a bang. The af worked but it wasn't sounding so good… I immediately took it to the Nikon service station which kept it for 4 weeks and changed the motor which they had to import… After that day my lens focusing speed has reduced by a lot… THE WORST PART… It won't focus on any distant object… Its infinity focusing has been hampered… I used it on the d5000 and found the same problem… Is there anything i can do abt it or should i discard the lens?

Yes, return it to Nikon and tell them they didn't repair it properly.

Jim is right. Nikon decided to fix it, they may or may not have charged you but the fix was not done properly.