Query not getting resolved

On the inception of my contract Telkom debited my account with the contract amount of 299 in December 2018, I received my phone in January 2019 . From my previous experience with Telkom is that the amount will reflect in my account as a credit. I called Telkom after receiving my first invoice they told me that the 1st debit does not get allocated to account but Telkom will refund the amount after 3 months of which I did not make sense to me. I went to the app to lodge a query even today is still pending. I called them last week Monday after receiving my statement still the amount not reflected on my account, the call center agent was helpful told me to send the proof of debit then she lodged a query to me and I was told that it will be resolved within 72 hours, I called on Friday the 8 of March 2019 they told me it is still pending. I do not understand what is taking so long to just allocate a payment of which you have the proof of payment or it will never get allocated. If I did not follow up like which means I will have lost my R299 as Telkom does not seem to allocate customers funds accordingly. And another thing that I want to know is that will I get compensated in interest for the period they held on my money for no reason. Currently I have to pay them the axact amount that they owe me why not offer it. I am really not happy with this issue.