ADSL_No reply and No Connection

We have app****/ordered ADSL 21 May and received a ETA of 7-14 business days, which then changed to 21 business days. Expected connection 10 June. Our ADSL has yet to be installed. (29 June 2020) called the call centre to more than 10 times to receive a different excuse every time. Their Supervisors are pathetic as they are never available when asked for and after numerous escalations and empty promises not once have they returned the calls we have been promised. Sent an email to the complaints department 20 June documenting all our communications, of which we have also not received a response. Pathetic customer service!