Beware of this unsolicited phone call scam - especially seniors

Yesterday morning my mother received a call saying there was a sudden increase in activity on her phone number and that services will be temporarily suspended within 2 hours and to press 9 to know more details. She is not too tech savvy which can be frustrating at times but also thankfully because she does not know how to operate UPI transfers to be scammed. She told me about it and I said it was definitely a scam to target gullible people. 

Today morning my father gets the same call and he said he was close to pressing 9 just to know who was calling but ultimately decided against it. 

In the past I have received similar SMS threatening disruption of service and asking to click on certain links but this is the first time getting an automated phone call

Has anyone else experienced these calls? Any downsides to pressing 9 and possibly connecting with a scammer on the other end? 

Do spread awareness to your family members and friends especially senior citizens parents/relatives and other gullible people who may not be familiar with such scams and may end up transferring money to them.