Terrible service by Vodacom technical

Vodacom technical division is truly pathetic. I have been liaising with them via Vodacom Bluff from mid last year right up till now regarding no reception in my dads house. My dad and mum are 68 years old and have heart conditions, so it is vital for us to keep in contact with them at all times and for them to make emergency calls if something happens. At the moment the only time that they can get any reception is when they go outside the house at certain points. From last year i have spoken to Vodacom to sort the problem out by installing a booster in the property but nothing is done as yet. All they say is that they have to call the line to test the reception and i keep telling them that they wont get hold of my dad or mum due to there being no reception. All that happens when you call them is you go direct to voicemail. To top it all off they both have Red Vip Premium which cost over R 4000.00 a month for both lines. This is absolutely ridiculous from Vodacom as there should be some value added services that they should keep to. I just hope they do something about this soon.