There are no rewards that can pay $1500 unless it's something like a
EOS Dividend website which pays dividends. But still the amount won't be worth as high as $1500. It may be like Waves that gives away free tokens worth $5-$50 sometimes.
Unless someone is incorrectly using your address, there's no way you will receive such huge amount. Can you please share the screenshot of your account?
Because, that's the only way you can receive free money like this! Someone is incorrectly using your wallet address and not checking back their own wallet. It is not a glitch for sure!
I don't think any person can even do such a mistake repeatedly. Once-twice is fine but not every month.