Wrong billing amount

I have a contract with with telkom mobile, in March 2020 I phoned the call center to purchase a once off data bundle of 1GB , the agent that assisted me purchased a recurring data bundles for me. In April I phoned the call center again to stop the recurring data bundle of which they stopped but still they billed me for 3 more months which are May , June and July I have been trying to get credit for 3 months but no 1 is contacting me , here are my case numbers ***3 and ***5.