homeconnect system hacked

I upgraded my package in Jan 2024 to a 200/200 line from Feb till July I have not seen that speed, I then downgraded to a 50/50 line, this morning I received an email that in 2025 my line speed will be 200/200. I didn't do this upgrade and I won't because the line speed has never gone past 50 in the past. The consultant I spoke to see that I have been downgraded but can see why I was upgraded for 2025. This is extremely frustrating when you can't identified who is making changes on my profile without my consent. I want this matter rectified and I want my line not to be changed from 50 to 200. I also want my statement for 2024.