Dissatisfied Customer Supersonic ISP

I’m extremely disappointed in the service I’m getting from supersonic. This is my second month with this ISP and already I’m NOT getting what they advertising. Their rating is extremely high on google but in my case it is the opposite. The WhatsApp line is limited when it comes to problems solving and the customer care line you never get through to an operator. This is so frustrating having the top package in their Supersonic F-LTE packages. I’m paying R999.00 for their 400G LTE package but experiencing extremely slow speeds. I’ve switched from Telkom to Supersonic thinking that the would be better, but they are even worse than Telkom. So frustrating!!!! Anyone knows a reliable ISP??