Student needs help with filling a hole in mesh/polysurface

I need some help trying to fill a gap in an iPhone 5C case that I found. I tried using the meshtoNURB tool to turn it into a polysurface and filling it but there’s still small gaps. I asked my teacher for help but he doesn’t know what to do either.

The attempted filling of the polysurface is here:

The original mesh is here:

Hi Brett, why make it a polysurface? What is wrong with the mesh as is? If you want to remove the cutouts in the back, First Weld the mesh at say 10 degrees, Explode, Delete the cut-outs and then join everything back into one mesh. Then, FillMeshHoles.