Unauthorized charges

I’m so frustrated. I cancelled my services ( WiFi and mobile in August. I even got a refund of $4.97 in September. Then last week (now we’re in October) I got charged $30.81. After calling on 10/17/26 apparently they never canceled the mobile line so I was told I would receive a refund for the full amount. To this day I have not gotten the refund and I just got ANOTHER email that I have an upcoming payment of $51.98 in November. I don’t know what to do anymore. I’m tired of calling, if you record phone calls you will hear me asking plenty of times on each phone call if they’re sure I won’t be getting charged and they have all confirmed I won’t but somehow keep getting unauthorized charges.