VL Health Unauthorized charges made to my credit card after initial purchase Internet

I made a small purchase for one product on the internet around February 2016. What happened then is that I had 2 charges. 2 for two different products and 2 for shipping.

Since the charges were relatively small, I didn't dispute them. But about one month later, 2 more charges came on my credit card without any warning whatsoever and they were much larger than the intiai ones.

I called VL Health asking what this was for and they said my 30 day trial was over and that I would now be charged. There was no mention of a 30 day trial on the internet nor when I received product nor via email.

I threatened to dispute the charges with my credit card company and they said they would give me a 50% refund if I didn't dispute and they would take me off their list.