Almost certainly, a native Russian speaker wrote the original material, correctly transliterating the Russian “f” as “ph”.
Any English person with a good education would, on hearing over the telephone the business name 'Alfa', write it down as 'Alpha'. That is the normal English spelling, not only in England, but in many countries. It is the favoured spelling of 'Alpha and Omega' in the Bible. In the respected opinion of my good friend Google the 'ph' version is more common than the 'f' version.
Sorry, Guardian, you get an F-. Or should that be a PH-.