Help not given

I would like to voice my frustration with regards to the service MTN shows to their contract clients I'm in utter regret with taking the contract by converting my number because now every month my services are being cut they either debit me before time and demand i pay extra cost or they don't debit me at call and disconnect my services ,when i call in not even one call center agent can help when i request to speak to a manager they either drop the call or keep me on hold for so long without a way forward of opening up my services i have forwarded proof but my services still remains cut Nosipi at MTN and all her colleges keeps dropping the call on me I'm very frustrated and need serious help