Kass - I think it's unlikely that your landlord will be able to provide you with that level of detail as staff time per tenancy is not recorded. Information on expenditure to your flat will be recorded however and should be fairly simple to obtain.
Inevitably some household will have had more time/money spent on them than others. I imagine that you're concerned that you've paid more money in rent than the cost of the service you've received? this could be the case, but equally others certainly will have received more.
As with or beloved tax system some people pay more into it than they get out but that forms to root of a democratic society.
The most useful information I'd imagine would be the average spend per property which should be detailed in your landlords annual report if they publish one.
the risk of course in only paying for what you get out of something is that you're not able to spread the impact when something goes wrong which is exactly why we don't receive a bill for £20k if we break a bone and need hospital treatment.
If RPs had more money I can guarantee you that the fist thing they'd spend it on is additional investment in its existing stock. The idea that there might be spare £ floating around is a long way from the reality.
This brings us nicely to perhaps the crux of the issue. In being driven to be more efficient by the govt smaller organisations have been driven into mergers in order provide cost savings. Larger organisation then become harder to scrutinize on a local level and customers have less trust in them.