
Pay an appropriate salary for those doing difficult large scale IT operations.
Again, get some IT Professionals in your recruiting process who will set up proper interviews.
Fix your awful recruiting staff, get some IT professionals who will make correct decisions versus just sales people scrambling for money so they can actually pay their bills and enjoy their life.
Your technical recruiters are awful, and it's because they get paid terribly. Straighten your ship and pull yourself together. If you want quality IT professionals you need technical recruiters that are TECHNICAL and actually understand what they are dealing with.