Checking received voicemail SMS on Vodafone

Hi,I'm using Vodafone's Prepaid service and received the following SMS today from a number I do not recognize:" Hi. I have sent you a Voice SMS. To listen, dial (*0*)(free call). To Listen again, dial (*1*)(75p/min). To send Voice SMS dial *Mobile no(75p/min) "(1). I've tried dialing both 0 and *0* but to no avail. The call either doesn't go through or I get a message saying I've dialed a wrong number. Calling the CC line is not helpful since they tell me that I have to dial the number I received in the SMS to be able to listen to the message. Any idea what else I can do to retrieve and listen to it?(2). And, if I want to send a Voice message in turn, do I dial the number with a "*" (asterisk) added to it??? Any suggestions would be much appreciated....Thanks !
I have written to your CC helpline, but believe it or not, this is what I have gotten in reply!!

" Delivery has failed to these recipients or distribution

The recipient's mailbox is full and can't accept messages now. Microsoft Exchange will not try to redeliver this message for you. Please try resending this message later, or contact the recipient directly."

This has happened 3-4 times now. You need a bigger inbox!!

Hello Sir/Madam,

Thanks for writing in. Please share your number with us here Vodafone India - Complaints - Requests - Enquires We'll contact you with assistance at the earliest.

Vodafone Customer Care