Online market problems--what should I do?

(This happened to my mother, but I'm going to state the question in first person for my convenience.) A while ago, I bought a Louis Vuitton travel bag for about $300 on one of those Ebay like online market sites, where just about anyone can buy and sell. Because many uncertainties may occur when purchasing and selling items, it is a rule on the site that the buyer and seller must send the check and the item sold on an arranged day; so in other words, AT THE SAME TIME. However, after sending the check, I awaited the arrival of the bag, and seeing how it did not arrive on the scheduled day, I contacted the seller to see if anything was wrong. She pushed that she did sent the item and that it should arrive shortly. Luckily, the item did arrive. However, I took at look at the track number, and it turns out that the item was sent the DAY AFTER she received my check. This was the beginning of my unease. Another point: In her description of the bag, she stated that the bag was in very good condition, (which was the reason for the high price). However, I inspected the bag and found a lose nail here, and a torn string there, and so decided to return the bag. I told her that she did not mention these things in her description and thus the sell a little deceitful. She agreed to accept the return under a condition. She asked if she could send the check in ONE MONTH, because she did not have any money at the moment. I told her that this was unacceptable. I was feeling quite a bit uneasy about this transaction due to the previous episode. I tried to reach a compromise, telling her that if she could send a check right now, that I would not cash it at the bank until a month later, or until she gives the OK. However, she said she could not do this, and ignored all my messages afterward. Not knowing what to do, I went through her old messages and found the contact information for her friend (lets call him Joe). I contacted Joe and he said that he would tell her to return my messages and phone calls. But nothing happened for the next several days. So I called Joe again; he said he did not know what was going on, and that he would tell her to stop ignoring my messages. But nothing happened again for the next several days. By now I am very nervous, and I told Joe that if she continues to evade me, I will put her name on the "black list" on that site. Hearing this, the woman finally contacts me saying that I can "put her name on the black list or whatever I want" and that she was so offended that I would do this, that she cannot accept the return! What should I do!? Is there anything I can do about this? Is there a legal way of dealing with this situation? I am desperately in need of help.

4 weeks ago - 2 answers