Oversell and Underdeliver

We got rain just before lockdown - 5G R999/month. Unlimited, unthrottled super fast internet. Was good in the beginning. Downloads speeds of nearly 300mb/s. Now if we get 10MB/s download and 1.5 mb/s upload we are lucky - That is with a full 5G signal on the router. Obviously oversell and underdeliver is just part of the busines plan.