Incorrect billing

I called last month checking why I'm billed so much, the consultant told me my other contract is not canceled as requested n she's escalating it for cancelation. Sadly to find that again this month I'm still billed double n when I call today I'm told the cancelation was send on the 18th of May 2021. The consultant confirmed she'll follow up and call me for feedback. Can I pls get my billing corrected.