The customer was informed in advance of the technician appointment that he must grant the technician access to TAE and APL. How exactly the customer manages this is his own business and not that of o2. O2 does not, of course, have keys to doors in the customer's house. 
If the customer does not comply with his obligation to cooperate and if it is therefore necessary for the technician to make several trips to the customer's home, the customer may be charged for the costs of the additional trips required. See price list. 

Hello @Sergipolo, welcome to our o2 community :-)

In many cases the activation of a DSL connection can be remotely. Nevertheless there may occur circumstances that make a manual activation necessary. 

If you can not grant access to all necessary infrastructure in the building in most cases a facility manager may be reached by phone if you tell him from the apointment in advance.

I am sorry to hear trhat the technician did not arrive at the time that was arranged but it seems like he tried his best to get your connection activated. Please excuse any inconvenience.

Regards,

Lars