Horrible service from Rain

So after I wrote a review about my experience with Rain I got very optimistic that my struggles will finally be over as I received correspondence from Thumba Mthombeni who works in Rain customer support. I was advised to "keep the device on while the network team is still optimizing the sites which are giving issues", I'm quoting the exact wording from the email. Fast forward to 2 days later, I'm still enduring horrible download speed of less than 1 Mbps from Rain. Whereas I'm still paying R479.00 for 10 Mbps which was promised in their adverti*****t but never delivered. Even after sending a follow up email nothing is done and response from them whatsoever, and I'm not even shocked anymore. Anyone out there who's clued up, kindly advise if this constitutes solid ground for lodging a formal complaint with ICASA. More so, can this be classified under false advertising as well? Because I know very well that I'm not alone in this struggle. There's even a group on Facebook formed for disgruntled Rain customers and the stories there are shocking. I had initially thought of ending my relationship with Rain, but that is not a remedial action as they need to account for this rather unfortunate treatment of their customers. I'm not even surprised that of all the 5 major ISP's in South Africa, Rain came last on the latest Mobile Network Quality Score report. One would even go as far as calling it a ****.