Useless customer service

I have a contract with vodacom, my account was in arrears for amount of R1300. In the month of June I paid the whole amount using the app. Still now vodacom cant locate my money. Even when I send them proof of payment several times to their Email. Called them several times they will give me the supervisor emails to help which they don't. What hurt me the most is that the bill keeps on growing. They are not wiling to help.