Impossible appointment to attend or cancel

Hello, I am from a diverse ethnic background and I live in the North East Essex area. Early in Dec 2021 I was taken to hospital due to my heart beating really fast. As the paramedics could not record the pattern that my heart was making the Doc suggested that I should be given a portable machine for recording this and the doctor said that I will be receiving an appointment letter for an outpatient appointment. The letter arrived on the 23 Dec after I had left to work. The letter stated that my appointment was on the 24th Dec and if I could not make the appointment I should call the office on the 23 Dec before midday. I tried to contact the office and called various cardiologist related offices and a nice gentleman said that we would be sending an email to all cardio offices to said that due to my Catholic upbringing I take the 24th Dec as the main Nativity celebration, and hence I have taken the day off to attend Mass with my young family. The week after I received a letter stating that due to my no show I will have to go through my local GP to be referred to the cardiology dpt at the Colchester Hospital. .

How is it possible that some departments are able to send details of appts by text and how is it possible that I now have to start again when I couldn't attend the first appointment sue to bad processes at your end