Fibre slow speed up to 2mbps

For the last month, I have called vodacom every week to complain about 1 thing only.... slow speed on fibre internet connection. I have been sent from pillar to post with tickets logged and closed without anyone speaking to me. Because their only mode of contact is to call the customer. I have asked to escalate this matter and Jason the TL promised to take ownership of my call said he would follow up with me. After insisting on speaking with a manager thinking that maybe he would really help. But then I ended calling again.the next TL at least told me that I could give an alternative contact number for back office to get hold of me, which they did and spoke to my brother as they cannot reach me on my number. Elroy then said he will send all the information we passed on to them. Speed tests we have taken over the last month shows that I am getting speed of between 2 and 11mpb for a 25meg line. Now the first 3 months was fine and then the lagging starts. As soon as I switch on my laptop the connection goes off and on all the time. I am suppose to work and have lost so much money due to internet issues but I'm still paying the R700 every month. I don't see vodacom asking me twice for what's due to them. My kids have the same line but through telkom and not vodacom and they live just around the corner. How does open serve work through telkom and not vodacom. I just want a technician to come out and help me but still no response from vodacom since Sunday when they called. I no longer want this product but still would like to have someone take action and actually respond to customers. The service I have received is pathetic and no ownership is taken here. I'm paying for something that does not work.