Does Avis not pick up calls?

Good day<br> <br> I'm trying to amend my booking about 2 hours before the expiry of my rental and absolutely no one at the call centre and Cape Town International is picking up. What nonsense is this? If you don't pick up then how am I suppose to make arrangements in respect of your car? What a pathetic company.<br> <br> Budget rentals next time again because I never have this problem with them and they're so friendly.