Credit on statement

Good day

I have numerous references from Cell C since July last year. Even this year 2023 January 16, I called to be explained about the credit I have with them from my statement. They don't call me nothing is happening. What to do next. I requested them to call me on my alternative number due to network problem. Last time i called they close the matter without including me. Still today it's not solved. Still my statement shows the credit. My bill is up to date. Thank you