No idea about refunds. I'm guessing you are trying to squeeze in a mobo/cpu swap with available funds.
Opening up the Northbridge on Phenom/Thuban cpu's can yield huge gains in cpu thruput without adding any voltage or very little, and thus little or no extra heat. Like 25-30% more depending.
Before you do anything hasty, keep in mind that if you are going to replace the cpu/mobo, the Intel solution especially with a 4690k, is the stronger performer over a 990FX/8350. But it is also significantly more expensive, especially if a new psu is needed.
So for example, if going the 4690k route means you need to use an underperforming video card for like 6 months due to budgetary restraints, versus 990fx/8350 and keeping the R280, the latter gives you a better gaming experience for longer.
If you want to do the cpu/mobo swap all in one shot, and then buy say, a R9 290 a few months down the road. ( they are getting pretty inexpensive these days), that would lead to a pretty solid upgrade over what you have now with a very noticeable increase in performance.
A 6850 is still a reasonable card for 1080p gaming, so doing that would not be the end of the world.
Again, remember that a motherboard swap almost always means needing a new copy of Windows, although there are ways around this. Like installing your current copy of Windows with a fresh install and calling Microsoft to get them to allow verification of the install as a legitimate copy. However this is not a garanteed thing, and you don't want to count on it happening.
So my advice to you is to decide which way you want to go platform wise, and budget and buy from there.
As my sig shows, I wound up with a 8350 and an R290x at the end of my upgrade path, and the 8350 is no slouch.
You can always buy the 4690k. look at the pretty box for a month or however long, then buy the Z97 mobo, and go from there.
Or buy the 990fx mobo, install it now, and then buy the 8350 and install it when it arrives.
Your 960t. if you can get a good overclock out of it, northbridge especially since that yields the biggest gains in cpu thruput, is not holding your 280 back as badly as some would have you believe. Yes it bottlenecks it somewhat, but you can still play your games right? I mean, you DID notice a difference going from the 6850 to the 280. ? A pretty significant one?
Sorry but with the vast array of possible computer configurations, I can't give you a simple " buy this and it will cure all your ills" answer.
At least not without taking budget in to the equation. If money was no object, we would just all throw $10,000 USD at Digital Storm and tell them to go nuts.
FX8350 or 4690k are your real choices, and all other spending revolves around your choice. including what order you buy things in.
If you want to keep everything you currently own, and OC the Thuban, head over to the AMD overclocking thread, and post up all your system specs and ask for help with the overclock. I follow that thread. This is the method that costs zero dollars, and gives you time to make a long term decision. While still being able to use your PC.