Ugh. Well it doesn't sound great. If you've turned the pressure control counter-clockwise all the way to the stop (presuming it has one - all of my regs do) and the pressure keeps rising it sounds like there's something trapped in the regulator valve that won't let it fully close.
One thing you can try:
- fully close the cylinder valve
- remove any tubing from the regulator output
- if the regulator has a shut-off valve on the output, open it fully
- turn the pressure control knob clockwise multiple turns like you are going for an insane output pressure
- get a good grip on the cylinder/regulator
- then open the cylinder valve to create two or three short blasts
The hope here is that there's some bit of debris trapped in the regulator valve body (very tiny orifice with a tiny pin valve) and by opening the gap in that valve and using a blast or two of high pressure it'll clean everything out. To check to see if it worked, turn the pressure control knob fully counter-clockwise to zero pressure, open the cylinder valve, and see if the pressure follows the control knob as you slowly turn it clockwise.
If that doesn't solve the problem I would have to believe that regulator is defective and if under warranty should be returned...
Cheers!