Of course ebay are aware of it, but there is no way they can stop it. The fact you hit 3 and spoke to someone, your number will be sold to scammers all around the world. I suggest not answering calls where you don't recognise the number. If it's important, the caller will leave a message. However, be wary of the messages because sometimes the scammers will actually leave a message. 

Don't fall for the PayPal one either. The call will be something along the lines of "you've made a purchase for $800, if that wasn't you, press 1". It's a recorded message and it will even go to message back with the message.