Sorry if this reply sounds harsh….
Are you happy with the price you paid for a second hand set of wheels – Concidering the dented rim?
If the answers yes, then stop stressing.
Now the more likely answer is that your not happy with the product or price you paid (as you posted on here to say so) and you should be contacting the seller to send them back for a full refund – although this is alot of hassle / work (hense the justification searching on a forum).
If the hassle of sending back the wheels out ways the cost saving and additional hassle of finding a replacement set of wheels then…… keep them.