Shocking "service" (none) and no responses

I have been waiting for a resolution to a non function landline for an 83 year old pensioner since 26 Feb 2023. Apparently they are working on the problem - the account manager can reach me for some apparent billing issue they have BUT cannot provide a resolution to my Mom's lack of phone. No feedback, no response via email, whatsapp and facebook messenger - I am way beyond words at this stage. I did however receive my monthly bill like clockwork on 28 Feb and 28 March - EVEN without service