Unfair Policies Leading to Disciplinary Process

My question involves labor and employment law for the state of: Delaware

I work for a large company as a supervisor of marketing/lead generating for the Sales office, a while back the heads of the marketing department made us all sign documents stating we were responsible for sales generated due to leads we were scheduling. The Sales office (a different department) has low sales of our leads due to mainly in part to very high product prices, and customers who are rejected due to bad credit, also if a customer does not purchase the product on the day of the appointment but purchases at a much later date we do not get credit for this sale. in February of the 142 actual appointments generated only 12 were sold by the sales office, Due to this the company has started my "Coaching" process, each level of the 'Coaching' will have to be signed by me, up to my termination.

Is there anything I can do

Based on what you posted, I don't see anything illegal being done by your employer.