Today I helped a client who needed assistance disputing a charge on their credit card. They were duped into purchasing a piece of software considered to be malware. (More on that later.) During the process, the credit card customer service representative instructed my client to call the phone number listed on the transaction. They said the rules are that the customer has to make an attempt to contact the solicitor to cancel the charge. I told the rep that I did not think it was a good idea for my client to call the number and risk having her number added to yet another robo call list. The rep was resourceful and looked up the instructions for blocking caller ID. I have not had this need so I wasn't familiar with the process, but I was happy to learn about it.
We first tested it out by having my client use their landline to dial *67 and then my phone number. I showed them my screen so they could see what it looked like. Once we were confident it worked, we dialed the toll free number of the malware company. I really did not like this part, but the credit card rep told us that it was a standard protocol that needed to be followed in order to dispute the transaction and that this happens a lot. They said they see this a lot and don't expect there to be a live human on the other end. Sure enough, it was only a recording when we called it. Now, if ever it would need to be investigated again, there is a record of the steps taken to dispute the charge.
I hope this helps should you find yourself in this scenario.