Disappointment with rules Fitting of Kingdom Doors!!

I am solely not impressed by your installation rules/procedures, there is not enough explanation or clarity when it comes to your own contractors for fitting your doors, it feels like a financial Rip-Off. I paid R4000 for 2x doors installation, of which I was informed old doors, frames will be removed, material is brought by the contractors, and I do not have to buy additional extras, However on day of fitting, I was advised to employ external builders to detach the old doors and frames, put in concrete lintel blocks and plaster the door as they (KD installers) couldn't do it. So I hired other professional gents, bought my own building materials such as building sand, plastering sand, cement , bricks and concrete lintels as advised, so the construction can continue. And of course getting external help means the owners is on me the customer to repair/fix and plaster the house cause it's now my damages, all Kingdom Doors does is just fit in the door, plastering is done by those I hired. I am absolutely disturbed/unsettled that I paid so much for a service which was hardly rendered to me, and I am still expected to pay for the labour of external employment? that is completely ridiculous of Kingdom Doors