Change installation date on the DAY!!!

I have recently placed an order for an ADSL line coupled with a land line to my new residence in Erasmia Centurion. After placing the order i was provided with an installation date through an SMS received. With this date in mind i had app**** for leave at my company so that i may be at home to receive the technicians to carry out the install. I called the call centre on the day to confirm that all is in order, they said yes and i should expect the technicians between 7:30am and 16:00pm. at around 11:00am i received an sms stating that the install is moved two days ahead!!! this is unacceptable and poor delivery. I have tried to call multiple times to get the technicians out as i am not able to get another day leave. I would need to take unpaid leave of which i cannot afford!!.I had called to escalate the matter, i was then provided with a reference number, and was told that i should expect a call between 48hours and 72 hours to resolve the issue! the worst part is that the issue needed to be resolved on my original installation day. To date i have not received any call but further SMS to say my installation will occur on the new dat of which i still feel is unacceptable!