Unfair billing practice

After my last review an agent called me only to purpot that Rain supposedly keeps service running for months on end without payment, this after I personally know service was cut off literally day after payment wasn't made. He then further went on to say clients "misunderstand" whole month tto month thingy and said billing department will investigate my matter. I then went on to get a text to say my "debt" has been handed over to nudebt and more hounding texts about defaulted payment. And I still maintain that I didn't use Rain data for 4 to 5 months, there was no service or connectivity but nonetheless I'm expected to pay. I wish the Ombudsman would have a look at these providers because it's really really unfair and I know I am not the only one treated this way by Rain..