Member is harassing me through messaging to lower my price

[bindisvdali]

There was a member who continually writes me, harassing me to lower the price of an already heavily discounted item. I have told them no and have told them it is not a best offer item and it is not going to be lower. I have blocked them from actually purchasing from me but I don’t know how to stop them from harassing me. How do I do this?