Pathetic Client services

Roughly a month ago i started experiencing issues with my wifi connection where at times the connection would be so bad that it will kick out all the devices connected to it. At the time i though it is due to me being on a 50/50 fibre line and that the bandwidth being used is at the max and that is what is causing my issue, I proceeded to upgrade my line which went live on the 04/03/2021,but for the first few hours of it everything seemed to be fine, but later that afternoon close to 6pm i started experiencing the same issues. I left it till the saturday the 06/03/2021 when it got so bad that even my lan connection started having an issue. I called the customer care and the agent then advised me that a tecnician will be coming out to my place to test the connection, on the 09/03/2021 i received an email stating that they could not find any faults with my connection and that the case is closed. This all was done without a technician coming to my residence to test anything, when i phoned in to question this i was told they could test my wifi connection from the comfort of their offices and that a technician wont be sent out unless i call them again once i arrive home to do exactly everything i did on the first phone call