No invoices for month

I did not receive printed invoices for the last 5 months. This has been already reported twice to the local Cell C shop without having any effect. I never agreed to or ordered anything else then proper paper invoices for my 4 contracts. 3 of them are on a monthly renewal basis. They can and will be cancelled anytime if the situation does not change. Since I spent already way too much time in trying to resolve the issue, I do not wish to be called by some service agent, who has no idea what the problem is and bothers me for half an hour just identifying me. <br> I do not accept any longer that Cell C debits amounts without issuing a invoice, btw. last month's statements are even not available online.