IMO, I get the feeling you are not fully disclosing all the events that led to your termination. Having been on the managers side of the fence, you better have a good dispute in regards to the other 3 write ups that you make no mention of in your post. Sometimes, people just don't fit with companies and/or the job, and maybe this is one of those circumstances, and you are not giving enough information to determine otherwise.

BTW, if any product sits anywhere, for any length of time, it is not "all profit".