Number keypad during automated phone call directory DOES NOT WORK

The keypad on my phone works just fine. The problem is with the answering machine I am calling which does not recognize the number signal being sent by my phone to it. I am assuming it is an old answering machine and the tones from a mobile phone are different than a land line. Is there a way to change the mobile phone signals to sound like landline ones? In the old days land lines were either pulse or tone signals. This has also happened a couple of times when asked to rate customer service by punching in a number and the automated machine does not recognize my input.

I hear the tones, but the receiving automated answering machine does not respond to them. Could it be a volume problem?