A service call? Seriously? A syadmin (or operator if it's a big place) can't see the yellow light on a disk and replace the pack with in-house spares? Have we become so inept as an IT community that we can no longer do a walk-through of our machine room and service simple things like this? Maybe we do deserve to be outsourced.
And if one must have a service contract such that only the vendor can touch the hardware, (why would you do that? never mind) wouldn't you negotiate a provision that includes drive replacement (as drives are consumables that must eventually be replaced) without being charged for an "office visit"?
First off, are things so bad you still have to do physical inspection of the servers? Where we work, there are multiple monitoring systems and they don't expect anybody inside the data centers unless there is a change order for work of known parameters. Beyond that, it's not even the IT community in many cases but the business community that will all too easily not spend the money for the protection measures the IT department requests, decide to go with the said vendor, and not make the changes to the contract that the IT department requests (if they even get to see the contract before its signed).