Hi Vinny,
I had similar issues with mine. I was convinced it was broken as I couldn't get anything near what I would call a useful tone. For the first week I contemplated taking it back. I was looking for high gain tones and really struggling. One of the best things I did was to drop the high cut on the cab to a point where you could clearly hear it taking all the top end out and then just increasing it slightly. This took out all of the high 'fizz' that was causing a lot of my issues and started to make it sound more realistic. I also found when changing the mic type on the cab block to give my ears a few seconds to adjust to the new sound as my immediate thought would be 'nope!'
I also found adding an EQ block at the end of the chain for fine tuning helped a lot.
I found a stock preset that was as close to what I was looking for and started tinkering with it. Small adjustments can make big differences so take your time.
I'm not far away in Birmingham, however I'm no expert so wouldn't charge for any time. I'm sure between the guys on here we can figure out what's going on for free!
What sort of sound are you looking for? and what guitar are you using? We can try creating some patches for you to download.