Connection cut off but payment made

Payment made earlier before their billing calling and emailing countless times no assistance I called in rudely so their consultant drop the call without hearing me out I cannot pay double amount The invoice sent showed good so that I’m not overdue but they have disconnected me How should I work without internet connection I called I text on their WhatsApp channel no one is assisting me I cannot be billed double and make payments and it shows I’ve made the payment earlier No no no