What to do if accused of trademark infringement???

Ok so i have been re-selling sneakers for a couple years now, November of 2014 i decide to open my wings and start an online business and purchase a domain (thefreshstoreus.com). Now recently (02-25-15) I was contacted on FB by a local sneakerhead claiming to own the trademark "The Fresh Store" since 2007. I did the basic whois search and found the domain "thefreshstore.com" is owned by a gentleman out of wisconsin (pretty much irrelevant). Honestly i would like my store name to be -The Fresh Store-but this sneakerhead wants 10k over the course of the next 10 years and 2% of my sales (didnt say profit). Im at a crossroads he lawyered up right away and gave me the offical "48 hours" to cease and desist or take ownership of my business threatened to take all my inventory because I am using his trademark. He doesnt own a store or website so i do not know what to make of this plz help thanks in advance i did all the searching i could but i could not find my situation anywhere thanks!