OK fair enough - if the fault is on the premises OR if I cancel within 48 hrs of appt or if I am not in when engineer calls you charge me £50. Yes I'll accept that seeing as there is nothing in the premises except a brand new router you supplied connected to the master socket which is not my responsibility.
Does this work both ways - will you pay me £50 if the engineer doesn't show or cancels within 48hrs? I suspect that this is a case of do as I say and not as I do.