Speaker purchase question

OP is dull.
1.   If there were no pix or mention of grilles then there were no grilles.
Why didn't you ask before buying?
Duurrr.

2.  The review probably stated they sound better without grilles, most do.
So you've got better than you expected, don't fuss.

One thing that can be helpful: arrange a phone call with seller before any significant purchase.  One still has to ask the right questions, but details are more likely to come out even if one doesn't.  Also good to get a feel for things, before send a chunk of change into the void.

Technically, the seller is right, however,  he/she is NOT an upfront or transparent seller.  I would’ve been majorly disappointed, both in the purchase, and with the seller.  Sellers have a responsibility to be accurate and also clear, and my gut is this was a premeditated omission. 

You can leave feedback that is fair and honest, while not being negative. I think the seller deserves feedback that encourages other buyers to inquire carefully before purchasing anything from him/her. 
Personally, I think you have a responsibility to leave feedback like this. A community like ours needs accountability, which you can achieve without being nasty.

If the seller is lurking on this post, I hope you realize you still have a chance to make this right.

reading all these replies, i do wonder... what was the seller feedback rating on a-gon?  good?  extensive?  

that aspect can be telling, and to me, it is a bellweather as to the level of attention i pay when considering a used item to purchase

'Caveat Emptor'... buyer beware. 
'Caveat Venditor' let the seller beware is a modern version.

If the speakers were sold "As Is"  then he was selling what you see in the photo with no implied warranty. It is what it is.

If NOT sold  'As is'  he clearly created an 'omission of detail' that lessens the value of the represented product. It's not unreasonable to believe the speakers would come complete unless he otherwise stated such. If this is the case, then he should at least be called out for his deceptive intent and warn the community.