You get Nerds and then Useless DANerds

Can someone please phone me regarding a project that was done in May 25. My wi-fi is down since the last week in May within a year of installation. I offered DAN an opportunity to solve the matter under guarantee. I provided the contract and invoice number and requested a service call. A technician came out on Monday, said the wi-fi was down (yes, that is why I contacted DAN), fiddled around and the wi-fi was up and he left. The wi-fi dropped again and I contacted him via e-mail early the next morning. Today is Wednesday, nobody has contacted me, but I received an invoice, for sure. Nothing about a guarantee, just a call-out fee. I have to register on some accounting site to solve the query regarding the invoice as I cannot reply to the non-responsive e-mail address from where the invoice was sent. What is happening, is this real or am I dreaming? DIAL A NERD, PLEASE CONTACT ME AS YOU MUST PROVIDE A SOLUTION, YOU INSTALLED THE WI-FI AND YOU HAD NO PROBLEM RECEIVING A LOT OF MONEY FOR THIS WI-FI INSTALLATION. ANYBODY OUT THERE????