First, if you're a new grower you'll be fairly impressed with what it will produce. My Apollo 4 has a custom spectrum and it does ok. The buds are airy'er, the light doesn't penetrate the plant as far as a higher-quality light. I wouldn't by another, but it does ok. Especially for the price ($150 delivered). Where you got screwed was buying a rebranded light instead of direct from China for $200. I wouldn't recommend it for that price either, but it's closer to being a reasonable value at that price. At $500, that's complete predation.
Second, if you purchased with a credit card you can dispute the the purchase with the CC company. Your grounds would be that the light was advertised as a 270w, but it only uses 195w. It's common for LED fixtures to be presented as their total diode capacity (90 3w diodes = 270w). But, they're always driven at lower current so they don't burn out in 5 minutes.
Some brands like Area 51 describe their lights using actual current draw. For example the RW-150 actually uses 150 watts. Most brands will mention actual draw somewhere in the description. Fortunately for you, GrowAce doesn't. You could use this to your advantage, that it was deliberately misleading.
The other thing which looks deliberately misleading is their claim that it covers 4.25x4.25 in flower. That's 18sq ft. At 195w actual, that's 11w per sq. ft. Even the most expensive, efficient lights like Area 51 are sufficient for 20-25w/sq. ft. People often use them more aggressively at 30-35w/sq ft. For a Chinese import using epi-whatever diodes, you need 40w/sq ft. People often run them at 50w/sq ft. That's why it's good for about 5 sq ft. Perhaps 2x3, or 1.5x2.5.
You could call them and express your outrage over fall advertising, demand a refund including shipping fees to return it, and inform them you'll open a dispute with the credit card company.
The only thing to be concerned about is whether they have any idea you bought it for weed and not cabbage. There are reports of predatory companies like HydroGrowLED "grassing out" difficult customers to authorities. At least threatening such.
If you buy a $20 Kill-A-Watt meter you'll see how much actual wattage the light uses. I'm estimating 195w because my Apollo 4 (180w) uses 130w, which is 32.5w per module. Yours has 6 modules = 195w. I think that's a reasonable extrapolation. It's somewhere between 185-210w. Definitely nowhere near 270w. You don't need to buy a meter to prove this.
Good luck. If you choose to keep it rather than all the negative stuff fighting them for perhaps 90 days (the dispute process), you could supplement it with LED lightbulbs.
I do that with a Chinese-import UFO. (<<link). They're more efficient than Chinese epi-whatever lights. You might need 30w/sq ft of these. 35-40w/sq ft if combined with your less efficient Chinese import light.
If you buy a new fixture, look at Area 51.
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