Will A 6.5 Ring Fit 7 Ring Resizing?

Ring resizing? - will a 6.5 ring fit 7

I have a diamond engagement ring is too big and Spence are only ~ 6, 6.5, 7 .... That have nothing to do between a half sizes.
Does anyone know a good place to change, that is the ring size, they could halfSize. or where can I find separators ring, which can be inserted into a ring to be smaller fit. Thank you!