Extremely poor service

I am very disappointed in Neotel. I am on prepaid and I need in invoice so neotel tells me that they do not give invoices to prepaid. Is this even legal? No matter where or what I buy, an invoice is always generated so why is is completely impossible for Neotel to give me and invoice when I purchase airtime? Secondly, for days now I cannot receive or make calls. I contacted Neotel twice already and nothing is being done about it. I think it is time to dump Neotel.