RAIN unilateral changing packages

I have been using Rain from October 2018 under unlimited off-peak. On Friday, 05 April i realised that i was not able to connect on the internet and when i checked on they web my package was changed from unlimited off-peak to pay as you use. When i engaged they claim that i am the one who changed it and they are not even accepting proof of my email screenshots that i have never even received such notification which one must get when you amend. Very very bad service - i requested someone Senior to contact me but it was like they don't care.