Bests & Worsts Reviews from Amazon

I bought seven of these cards (128 GB), which come with a 5 year warranty. Within 10 weeks, three of them failed. I tried to contact Gigastone, only to find that the security certificate on their website had expired over a month before. I still tried to fill out the online form, only the submit button wasn't functioning. I tried in two other browsers with the same effect. So, I found an email address on the packaging and contacted the company. In a reasonable amount of time (maybe the next business day) I received a response. The email did not seem like it was written by a native English speaker, but I was able to fairly clearly determine that they wanted me to send them a picture of the cards that were not working to verify that they had not been physically abused. This seemed perfectly reasonable, so I took a picture and replied to the message I received, including an image attachment of the three cards that failed the day after that. After about a week or so, I had not heard a response from the company, so I sent another reply asking if they got my message, or if they needed any more information from me (more images, tests they wanted me to run, etc.). That was over a month ago and I still have not received a response nor any replacement cards. I ended up just buying new ones from another company. I would still like to get my replacements (the cards worked fine until they didn't, and the others still seem to be working without issue for now). I don't like leaving negative reviews, but I don't seem to hear anything from the company, so I think it's appropriate to share my experience here.