Vodacom Fiber *****ing customers money by automatic upgrades

About a year ago I received a message that my fiber will be upgraded from a 25mbps line to a 50mbps line. I enquired and they told me that the smaller line is no longer available. In Feb 2024 I received the same message that my Fiber will now be upgraded to a 75mbps line. I contacted Vodacom once again and they transferred me to a department that asked me to sign paperwork to downgrade back to the 25mbps line. Now less than a month later I once again receive a message that I have been upgraded to a 75mbps line. When I phone they tell me the 50mbps line is no longer available. I do not believe them this is a way for them to make money. I am battling to get through and went through to general support that once again customer support said the smaller line was discontinued and put me through to another department that is not answering. They are no more than *******. So now I am locked into a 12 months contract for a 25mbps line yet getting a 75mbps and paying for the line I don't need and cannot afford and cannot downgrade nor cancel. *****s, their call centers take a chances to say the line was discontinued yet is still available online to register or subscribe. Last year I also placed a complaint on this platform, Vodacom responded and said they will contact me, I am still waiting for that call.