Bad service - Tec Glass & Aluminium

I have never met anyone as persistent as the lady from Tec Glass & Aluminium. Once the deposit was received, I got no communication from them unless I called them. Eventually I got ahold of them and the gentleman that came out to site was so rude over the phone telling me I must wait till they phone me to say they coming to fit my new windows. After waiting 4 weeks they came to do the work only to find out the glass was wrong coz the building inspector came to my house and now I cant move in my house coz they not a registered company. I'm trying to find out where there stay but didn't come right yet. Please be careful guys if who you use for this kind of stuff