See comment above: If liberals and conservatives both lose then isn't it a win for humanity?

People care less and less to understand the inner working for any given tech. They just want it to work. That being said you also have to take into account the pillars... Good, fast, and cheap. Pick two. Our industry is very like that of the nursing industry. Yes we get paid, but the conditions are rarely healthy. When you treat peogle like a commodity and pay them to just make the magic boxes work you will get what you pay for.

I think your main objective is to in as simple terms as possible relay the costs to the company of NOT employing you. Compare your SLA/OLA with vendors. Find 3 that are as similar as possible and average the cost of their service. Figure down time cost to the company, response times of you versus a vendor etc. Beyond that you might consider a weekly report that details your major expenditures of time. Use a ticketing type system or log all of your projects/time sinks. Detail everything you do that is more than a few minutes out of your day and present the reports weekly to management.