I accepted a job at an old employer. I should have known better as they don’t treat their employees well. The job is too much work which I told them when I was offered the job as I had time to think after the interview, I initially refused the job. These people are gaslighters and the manager is very unprofessional. The manager sent me an abrupt email asking why something was not done yet I was not asked, he is lazy and delegating his work to me and others. It is affecting my physical and mental health. I have raised the workload issue in an email and he chose to ignore it and let the supervisor deal with it. I only have to give a weeks notice. What is the best thing to say in the resignation letter? It is a waste of time trying to reason with these people.