windows and doors fitted?

ive had double glazing fitted-i went with this specific company as they specified 2/3 working days to complete as a team would be in attendance. I agreed although not the cheapest-as i had to book time off of work. Anyway 1 guy and his aprentice attended as opposed to the team which he informed me were deployed elsewhere taking the job four full days-top marks to the gentle man he worked very hard indeed. Then a further 3days for the slap bang plaster to appear and fill in holes between rooms! they now want to know how i intend to pay. I had to rearrange work for a further two days, luckily two as they tripped the alarm when installing the front door. Should i request any discount? also they have not returned key and when ive phones to establish when this will be they have advised i can pick up when i pay!!!!!em