Voicemail app not working on my cable box

I have been having the same issue for over 4 months.  It has been a journey trying to resolve this. Just had a Tech here and he said to just press *99 on the phone to retrieve my voicemail. He basically avoided the question and said he would "bubble it" to see if there is anyone else having the same issues. Told me not to call into customer service about this, I would just get somebody (foreign) who gives you wrong information. I went through 4 set boxes that I had to take back and forth all 4 times to the Xfinity store that is about 12 miles one way. Chatted with the virtual assistant, scheduled a service call. Waited and no show. Finally, got to speak with a live person and scheduled another service call. The previous person forgot to finish the ticket? I'm beginning to think they don't know what the problem is and don't know what to do or say.  My husband is very hard of hearing and prefers to read to voicemail. After all it is a feature of the phone line.   I have tried googling the problem and it only gives you a possible fix for the mobile phone not your home phone. Passing the buck hoping you'll forget. It's is very frustrating!  I hope they find a solution very soon. 

Good afternoon @user_e837ef, and thank you for reaching out on our Community Forums. We apologize for the frustrating experience and there is a known issue with the voicemail app. Our engineering team is investigating and we hope to have a resolution soon. Currently, our only temporary solution is to check your voicemail through the phone or website. We apologize for the inconvenience and appreciate your patience.