Voicemail retrieval

I am unable to retrieve my voicemail messages, callers can leave messages fine but i cannot get them. When i dial 121 the IVR prompts me to set up a password, i punch in a password between 4-6 digits and press # and the IVR tells me that the service is currently unavailable. This happens over and over.<br> <br> This has been going on for weeks. <br> <br> I have just called the call centre twice, on both occasions i was assured that its fixed.<br> <br> IT IS NOT FIXED, THE SAME ISSUE PERSISTS. PLEASE RESOLVE IT NOW !!!