Extremely slow upload speed!

Since it was installed, the opload speed was less than 1Mbps. The installed speed should be 20Mbps. There is a huge delay in WiFi Whattsapp calls as well as Teams or any other video calling. One can not communicate with the other person due to the delay. I reported it and a technician came to fix it. It was actually worse when he left with a opload speed of about 0,25Mbps. I can't even log into the bank servers!. I sent various emails for immediate cancelation, and spoke to the accounts department which promised cancelation. I actually have 7 (seven) reference numbers but nobody called back or even rep****. I reversed the firts bank debit order because the service is useless. It seems that one only gets a reaction when you complain on Hellopeter.