RAIN's No Contracts and Obligations ****

I took a RAIN sim for data and when I took the sim I was told, no obligations, no contracts, pay upfront and use what's available. Because of the network connection that was horrible and always battled to connect, I stopped paying and knowing very well there's no contracts. I have been trying to contact them for months because if I log in, a monthly amount was added. I tried to dispute and there's never anyone to answer on their number ***. I now received an SMS to say my account has been handed over to Easton-Berry attorneys for collection. To collect what exactly because there are no contracts and that's what they advertise. How do I get RAIN to clear this because I will not pay a single cent towards something that doesn't work. Their website has no contact details except this number and there's no email addresses.