Invoice request for January 2024

I sent a request to send me my invoice on their whatsapp on the 7 February 2024. I am using Vuma Fibre for couple of years now and I always requested an invoice and I got it. Now am told there is no invoice to be supp****. I told them I need this for my work. They sent me an invoice for last year. During same week I sent them an email as was to told my query was escalated to a finance manager. They responded to my email on the 11 February 2024 that they are attending to my query. I never received further responds. On the 19th I followed up again yesterday still nothing. I decided to call them they said a case was logged CAS-***-Q8Q3H2 I should follow up today. I called today still no progress and I requested an invoice with my full address for work purposes. I am paying for this service and expect a service when needed