Often what you had in mind for a piece doesn't match the reality when it comes out of the kiln. In this case, you have several options.
If you really hate the piece and don't want to wait, you can get it recycled by sending it to a scrap service. In the UK, major jewellery suppliers offer scrap services like Cooksons in the UK or Cascade Refining in the US. It's worth keeping a scrap pot in your work area so you can collect your scrap.
Often, you may find that although a piece didn't work for your original idea, it may be usable in other work. By keeping the piece on your work table, you may find inspiration strikes.
You can connect a fired piece of metal clay to unfired designs by using thick slip, a lump of clay or a mechanical connection like a rivet. You can also attach two fired pieces of metal clay by using Art Clay Oil Paste or metal clay mixed with lavendar oil.