teespring.com Unauthorized Credit Card Charges and Nonexistent Customer Service Internet

I have charges from teespring.com on not one, but two different credit cards for purchases that I did not make: one charge on March 31, 2016, in the amount of $104.71 on one credit card, and another charge on April 5, 2016, in the amount of $121.75 on a second credit card....very strange. I bought one t-shirt from this site and that was two years ago using PayPal as my method of payment.

I have tried calling their customer service number numerous times over the last few days in order to resolve these unauthorized charges, and I keep receiving a recorded message saying that "our phone support is currently experiencing much higher volumes than normal", and suggesting that I contact them via online chat, after which they disconnect the call with no opportunity to leave a message.

I tried contacting customer service via online chat on the teespring web site and received no response whatsoever during the chat session; the chat session was shown as active, but no one ever responded, even after waiting at least 10 minutes.

I have since had to contact the credit card companies to dispute the charges, and cancel and replace my credit cards. What a hassle.