Can putting the wrong type of gas in a car ruin the spark plugs?

I have a 02 eclipse and its a GT so i takes premium gas. but ive been putting unleaded in it for about 2 or 3 months and i havent noticed it running any different at all. well a few days ago i tried to crank it and it wouldnt crank but i think that was because of the battery ( it was corroded or something). well anyway i took it to a garage and they checked the spark plugs and they needed to be replaced and i was wondering could this be cause by not putting the correct gas in the car or could it have just been time for them to be changed. the mechanic said the previous owner oblivously didnt take care of it.