Bad service

I have a rain wifi which I was told it was a month to month contract. Everything went well up until Jan this year. My partner who's using the wifi was away from the 27th of Jan until April this year, wifi was disconnected and in storage but I'm told of a usage of 200gb usage for Feb. Again I'm now told I owe 2999 for feb until now. Tried to call customer service, spoke to a consultant who just wasted my airtime and time then eventually hungup on me. Why am I charged for months I didn't use the device? It says on your website that you suspend services if payment isn't made, how did i end up being charged then?