Poor customer service Cell C do not want to refund me

Ref*** I have purchased a whatsapp bundle on the Cell C app for my son early Feb 20. My son didn’t get the data. I tried again an hour later and again he didn’t get the data. My mom’s phone is also linked to my app and she then let me know later in the day that I have bought data twice for her. I then bought data on the cell c website for my son. I have phoned cell C the same day, but the lady didn’t log the call. I called again on 10/2 and was told that I made the error on the app, but they will investigate, but NOBODY phoned me back. I bought data again on 4/3/20 but to make sure that I do not make the same mistake I recorded the transaction and saw that that even though I picked my mom’s number it changes later in the purchase to my son’s number. I again phoned customer services and told them I have proof that there is something wrong and demanded to speak to a team leader. I spoke to someone who actually listened and undertook to phone me back, which she did. She said they will investigate and phoned back. On 12/3/20 I phoned again to hear that the reference number was closed as they could see that both number has data. I explained EVERY time that I afterwards bought data on the Cell C website as if I didn’t they would be left without data up to now. I want a refund as I didn’t make a mistake and have a video to proof it.