Worst exploitation service ever

Worst of all service ever, they call in month to month, i give them my banking details to debit from, they never do that, they never do that but will call the following month saying im owing, i have never reversed their debit order, not sure why they decided to cancel the debit order and why they are not debiting, to make matters worse their unit is forever damaged, last they gave me a unit which melted down to visible side, everyone could see their device, but it was hard to find a panic button, i call they fixed but for over a month their device is not working, they promise to fix but even now im still waiting