For people who accept temporary employment opportunities, is this the normal experience once starting employment begins?

You go through very intrusive background checks which include exposure of your credit bureaus( which requires you to provide reasons for derogatory collections which you are told it could impact your ability to do the job effectively), drug screens which require you to supply photos of your prescriptions, and all other typical background information.

After a 2 week long background check process, you begin the temporary assignment. You start training on the companies processes, and provided training manuals which only detail how to navigate a specific process, does not provide information detailing when/how to resolve problems you may run into if the process is done incorrectly.

You are trained with a permanent employee in your area of the company for approximately a day and a half. You take notes. You begin working on your own navigating the process without mistakes with the exception of small details brought to your attention and resolved. You are working on your own using the manuals and completing tasks correctly. Two days after that, a manager calls you in asking if you are REALLY understanding their process, and you have more to train on. A few days later, you still are not trained on additional processes for your position and are told you are not grasping the job, and NOT working fast enough.

Then you are told not to return to the assignment.

Is this how all companies treat temporary employees? Expendable???? Is this the experience of other people out there?

Why are companies not taking the time to train people allowing them to do the job the were hired to do?