T.S.
I would go back to where you got the glasses and see if they can adjust them to fit better or if they have frames of equal value that they will switch the lens's into. I have a son who has worn glasses since he was 3 and he will not wear his glasses if they don't fit right. He is 6 1/2 now and if his frames get bent in any way he wont wear them and we take them back and get them adjusted.
I was also surprised when I took him when he was 3 to get glasses he picked out the frame. I had some I picked out but he wouldnt wear them.