Redirected a client’s phone line and forgot the website for two weeks

probably the dumbest outage i have ever caused and there was no outage at all. client moved office in march, new landline, and they asked me how to redirect phone calls off the old number so nothing dropped while the transfer went through. that part i got right. their telco does a plain divert, you set it in the portal or dial a code from the old handset, and every call to the dead line lands on the new one. took about nine minutes. i rang it from my own mobile, heard it ring in the new office, closed the ticket and felt quite good about myself. What i did not do was touch the website. the contact page, the footer that every template pulls in, the schema block, and two landing pages the previous dev had built outside the theme entirely. old number in all of them. that was fine while the divert ran, except the telco only sells the divert in sixty day blocks and nobody renewed it, so on day sixty one it just quietly stopped.

nobody told me, because nobody knew. calls to a small trades business dont go to voicemail and get chased up, people just ring the next name on the list. we found it because i was doing a routine crawl for dead links and grepping the html for the old domain, and the retired number came back in the results, and i sat there for a second thinking hang on. three weeks of enquiries gone. no error anywhere, no 500, no failed request, uptime sat at 100 percent the entire time because a wrong phone number is not a status code. that is the bit i keep chewing on months later. i have alerting for the site being down and nothing whatsoever for the site being wrong. the contact details are one source in the theme options now and everything else reads from it, and i wrote a stupid little check that pulls the rendered homepage once a day and shouts if the current number isnt in it. it has fired exactly once, after a plugin rolled a template back. still no idea how many of those calls