Bad faith customer experience

Received an sms that my line was being suspended because of overdue payment and I should contact my service provider. Immediately, the line was cut. I could not even call the 135 number to get resolution. When I called from another phone, the automated voice said they were having network issues ‘goodbye’... without an alternative route for resolution. Sent email complaint... when I eventually got through early evening, I was told I owe an amount I know I made payment for. My line was reactivated but soon after, I received another SMS saying I had undertaken to make a payment of x-amount within a week, which I never made... the explanation was convoluted and made no sense.