I once installed a couple of additional TV points for a customer in an apartment and was given recommendation by them to the 'management' which got me a contract to upgrade the aerial mast on the roof and a couple of other jobs, including the addition of twin satellite - SMATV - to the block (24 users).
I duly installed everything and was paid for the final invoice, which included a maintenance one off charge for returning to check all was well in 12 months provide a comparison signal report for their records and advise on any further additions that might be required (DAB etc) based on resident feedback.
Fast forward 12 months and I return, all looks fine, signals play out and I send the report with another bill for the following year assessment, which is paid
When I booked access 12 months later I was advised another company had offered a free estimate for assessment of the equipment a month before, a company recommended by the initial apartment owner. They were offering Sky +/Sky HD for the block. This required - in their correspondence - a complete replacement of the kit I had fitted.
I made the decision then that it would be better to 'retain' the return surcharge I had billed the association earlier, as the administration incurred looking through their recommendations, correcting and picking myself/my jaw off the floor was better than arguing.
In the last year I've discovered the residents have been paying an annual £270 per apartment fee via the association, plus individual callouts when things - regularly - go belly up.
I have no idea what is installed upstairs since there are new locks in the service/access rooms, but it obviously is making somebody rich.
I'm in the wrong job.