What was the reason Mr. Blackpool to fire Mr. Blackpool? How did tom frame Mr. Blackpool in the bank robbery

A false key is found in the street and it is concluded that the safe was broken into with the false key. Bounderby immediately suspects Stephen Blackpool for not only has Stephen left town, but Mrs. Sparsit and Bitzer can testify to the man's ambling back and forth in front of the bank for several days before the robber took place. The crime would both increase his relative fortune and allow him to have his revenge against Mr. Bounderby.