Not happy with owing them for what I don't know

Hello Peter. My name is Siphiwe I stay in Sky City in Alberton. I lived in Soweto Braamfisher and I Dad a Rain simcard which was working perfectly until I relocated to Sky City in 2021.Rain's signal was very poor and I went to the Dashboard and called for help until I opted in Fiber. Because I was on prepaid with Rain I just stopped using it because I couldn't use my paid Data but to my surprise 2023 end of April I received a call from some lawyers saying Rain handed me over to them for an outstanding R295. 00 and I was so angry and am still angry with Rain because they have my email address and cell number so why didn't they call me if I owed them? I don't know why I owe them but I need answers because they didn't respond to my email query. Please help