Cell C Fibre via Vumatel is USELESS!!!!

Cannot explain my frustration with Cell C and Vumatel. Paid for more than a year for a 1Gig line speed and only received just under 100mb/s. Decided to downgraded to what I get so that I can pay for that. Now that I down graded to 100mb/s I only get 9mb/s. Customer service make you do test and lock tickets and then close it unresolved!!!