Accelerit or Decelerit ISP with speeds so slow.

I recently subscribed to Accelerit Fibre via Zoom Fibre. My experience has only been only "Decelerit" in all respects - customer service and most importantly broadband speed. I subscribe to a 50/50 Mbps connection and in the evenings only get about 3-10/5-20 Mbps. This is ****************. This problem has unresolved for about a month. Request for immediate cancellation has been ignored. Most frustrated.