Where/how to complain about a badly-handled hardware support case?

[01101001]

My DL360p Gen8 had a iLO malfunction that required motherboard replacement although the non-iLO part of the machine was fine. It took the 'engineers' 3 visits on 3 consecutive days to fix the problem and on the second day, they even messed up the machine (I think the 'engineer' didn't put back the CPU properly) so that one of the CPUs kept getting too hot and performance suffered. Apart from incompetence, there were other aspects to their unprofessionalism.

Although the case is now closed and the iLO issue has been fixed, does anyone know where I can escalate the case to bring to HP's attention the unprofessionalism of the 'engineers' who came to handle the case?

[Jimmy Vance]

My suggestion would be to call support, reference the closed case and ask to talk to a supervisor.