***** claim dispute being ignored

I've had a *****ulent transaction on my credit card. I tried alling *** a couple of times, but did not get through. I then called ***and I spoke to a person who I assumed was a discovery employee. It turned out that the ***number was intercepted by a *****ster, and that caused the *****ulent transactions to go through. I've asked on numerous occasions for the transcript of my call to be sent to me, as i have proof on my phone that I called at a specific time. WITH WHOM DOES THE RESPONSIBILITY LIE TO KEEP YOUR 0800 NUMBER SECURE. WITH YOUR CUSTOMER OR WITH YOU.