Is it rude to ignore a buyer if their offer is a lowball?

Hi! I have been selling for a while now and I have found myself becoming more lazy when it comes to responding to bad offers. The other day I listed an item and this buyer was nonstop bugging me about how had accepted an offer that I had never accepted (and not to mention it was $10 off buyers original offer) so I didn’t have the energy to respond so I just ignored her. She was blowing up my phone about this lowball saying she would buy it right then if I accepted it so I just never responded. I ended up selling the item at the price I originally listed it as. So it made me ask this question is it rude to never respond rather than blatantly disagreeing (or arguing) with a buyer? I would love to hear your thoughts!