Terrible connectivity, spikey with inconsistent download and upload speeds

For 3 weeks I have been experiencing terrible upload and download speeds on the fibre line. 4.86mgs download speed and 3.96mgs upload speed. Contracted to get 50mg download and upload. Reported to home-connect who said it was a Vumatel problem. Vumatel has checked the line and there are no issues. Home Connect has run diagnostics and still the same problem. I went with Home Connect because they had good reviews on Hello Peter. Terrible service and terrible fibre.