Disgusting service towards customers

I app**** for fibre and the order was cancelled by them. A sales rep called me and offered me MTN LTE services saying there is no fibre in my address yet I agreed but told him that the MTN service is temporary thing I will cancel it as soon as I have fibre, as I was planning to move to a place that has fibre. I was told I cancel anytime as it a month to month service Whn I cancelled they ignored my cancellation, I talked to them requesting to cancel more then once but my services were not cancelled till date. Now that I refused to keep on paying for service I no longer use and request to cancel they saying I had to serve notice before cancellation which I believe I did because I requested to cancel 2 months ago but they ignored me