Payment allocation

Good Day, I need help. Match 20th I made a payment of R800 to my MTN contract to cover Match and April. Early May I made a payment again just to push my accout and on the 5th my line was suspended and I was told that I pay less than what I was supposed to pay since the R800 was not reflecting on their system. I sent proof of payment on the 5th of May to this email: mateboho.kareli nothing was done, i also sent proof to bankingfinance on 16th of May nothing was done. 29 May my line was suspended again, I phoned and sent proof to clarance.mdima and nonhlanhla.mtambo still nothing was done, 18 June my line was suspended again and I phoned sent proof to bunolo.khonkhe, SVC_mtnsiyakhulawcc and lungani.mzobe nothing was done. On 20th of July my line was suspended again and I phoned sent proof to nondumiso.gumbi and SVC_mtnsiyakhulawcc still nothing was done, 5 August my was suspended again I sent to shaka.khanyilestill nothing was done. 18 August I sent to zamabhengu.bhengu still nothing was done and today my line was suspended again. Please help because I really don't know what to do now, I've been sending proof of payment since 5th of May but MTN still suspend my line and now this affects me negative on my credit score. Please help