No receipts for parking on sundays in jayanagar TTMC - Is it some rule or parking mafia?

Yesterday evening, I was in jayanagar, and I chose to pay-n-park in ttmc jayanagar instead of looking for free parking in the residential roads.
 When I parked, nobody gave me any receipt, and I also forgot to ask that time.

Now, after around 1 hour or so, when I come back and took my car out, at the exit on terrace, I stopped to pay at the fees, they told Rs. 20, and when I asked about the reciept, they said -" No receipt on sundays" - and "Hundreds of people parking here, nobody is asking for receipt, why you asking" ... also "jao jao, aage jao" and many rude talks as well when I insisted more on receipt.

Even, that Rs. 20 he asked me, is not the proper one. Because I remember, last to last week, when I parked there, they gave a receipt as well and charged Rs.10 for parking (as written on receipt). That time I had thought in mind that, why are they charging so less for parking, they should charge atleast Rs. 20 for 4-wheelers, I mean, better not loose revenue and invest that in good public transport facilities.

And see this sunday, I see -

(1) Rs. 20 instead of Rs. 10, and they said - Rs. 20 on sundays.

(2) No receipts, and they say - no receipts on sundays.

(3) Where is this money going? (That too extra looting)

(4) After sometime, will TTMC say that they are not getting any revenue from parking, so they would rent/lease that also to some other stuff?

(5) BBMP is all talking about making paid parkings in congested areas, which I feel is welcoming move, but then what about these parking mafias?

(6) If BBMP has to go the paid parking way, they have to go for automated ones, otherwise there are so many leakages in their system, money looted from public, not going to govt(public fund), and leakages in public(govt) fund as well.

Can any one suggest me, where and how to complain about these?

Deepak