Update on my bad experience with the parts dept, A...

Update on my bad experience with the parts dept, Alex, and the general manager. After they sold me a part that didn't fit through Amazon, and after Alex repeatedly refused to admit the part was wrong (even being so cocky as to imply that he couldn't make a mistake, saying "This is what we do," he was finally forced to admit that it was the wrong part. I then wrote a poor review on them, simultaneously asking for a refund. THEN, Alex tried to hold some of my refund hostage by saying that he wouldn't give me a total refund unless I took my bad review down. I told him that after he refunded my full cost, then I would reevaluate my review. He didn't like that, implying that he wasn't gonna refund The entire amount I had paid, even though I sent him the part of the extended warranty that clearly stated that he was supposed to pay me. I waited, hoping that he would change his mind. But recently I saw that he in fact held some of my money, just because I didn't change my review. So apparently Alex tries to coerce people into removing their negative reviews by holding their money hostage. Is that legal?