Fraud on my gm MasterCard, no help from customer service

As many of you know, gm switched from Marcus to Barclays on the 25th of August..on that day I got emails saying my card was activated and that there was a request to change my pin. I also noticed 3 charges that I def didn't make. I reported the fraud and also called Barclays to confirm everything went through. They claimed those emails were sent to everyone because of the switch, which seemed likely so I didn't think much of it. But I'm wondering, was a new card sent out? The card I had on me still said Marcus I never received a Barclays card. Also, they claim that the charges were not fraud because the chip was used and chips cannot be counterfeited. Customer service has been terrible, is there anyone else I can speak to about this? Luckily, it was small amounts but still they are charges I did not make.