To turf or not to turf

We recently lifted some block paving in our garden so we could lay some turf. Its turned out to be a much bigger job than we thought as there was hardcore and sand under. We have dug this up and added some top soil. The issue we have is that we ordered the turf before realising what was underneath so we had to lay it as it had been sat on a pallet for 4 days. However we need to raise the height of the lawn to the brick work surrounding it. Would we be ok to put more top soil on top of the turf that we have laid and then put another layer of fresh turf on top?