Inconsiderate

I went to Telkom last week in order to organise installation of a phone and ADSL line. The branch was friendly and helpful so I expected a smooth process. I then booked an installation for the 22nd of October between 7:30 and 12 pm and received a confirmation sms. I work full time so I arranged someone to come to my house in that time slot. Then, yesterday afternoon, out of the blue, I received an sms saying my appointment has been moved to the 20th of October. They didn't even give me 24 hours to make arrangements and on top of it they scheduled a full day appointment between 7:30 and 4pm. I tried to get my initial appointment back but it was no longer available.I then had to make emergency arrangements for someone to be at my house today but Telkom didn't bother communicate with me until 13:30 about their whereabouts. I don't know if Telkom assumes all their clients are patiently waiting until the day they decide to deliver the service they said they would but I am not pleased at all. I am incredibly disappointed and the most frustrating part of it is that Telkom is one of the biggest service providers in our country but their customer service is is non existant.