ADP Implementation Engineer III reviews

8 years with them, worked hard to learn new tech that was being implemented. I had asked about a promotion/raise and was told they had no reason to. I took that as I needed a job offer showing my value. I went out and got an offer that was a 50% raise and came back with it. I made it very clear that I didn't want to leave, but I was clearly more valuable than I was currently making. My manager took what I wanted to HR to get an approval, which he got. He approved it but when it came to upper management approval they asked HR what it would cost to replace me. HR said it would cost about what I was asking and also said "We find that when someone is looking for a new job then they won't be happy even with a promotion.", so the upper manager said that's the answer and goodbye.

Salary should be higher, workload overwhelming