So, it sounds like your issue is your vcore setting, perhaps a couple others?
If there was a problem with the cooler, it would also cause overheating at stock/default settings. What temps did you see when doing this?
If you had it setup to run PWM off a CPU or MB header, what they were suggesting likely was correct in attempt to evaluate whether RPMs were being set correctly. Not necessarily the #1 fix, but a good thing to investigate.
No offense, but this sounds like it is more your on your side and your overclock settings and not the cooler itself.
Far too often we see upset people because they assume that a cooler can handle any BIOS settings, even if they are configured in a way that is less-than-optimal. The cooler, no matter how good, can really only do so much because the temps being reported and valued are at the thermal sensors on the die itself and the capacity of the cooler is based on how well thermal load is transferred from the core, through the IHS, through the cooler heatsink/block and then to the cooling dissipation field.