Highway - Chocolate scam

Have you ever received 1Re change from any of the toll booth in NH4 highway? Have you observed that most of the toll fee along the entire NH4 highway is like Rs19, Rs39, Rs44 etc. Have you observed that you always get a cadbury eclairs chocolate instead of 1Re change. Well how does it matter after all its just 1Re. Now if I travel from Bangalore to Goa with around 6-7 toll booths along the entire stretch it's just around 6-7Rs extra one way. What's the big deal?  

At the first place paying for toll doesn't make sense after paying all the taxes, roads are the basic necessity the government has to provide. Well at least we have few good roads after paying these toll, so I shouldn't be expecting too much. But then the concern I have here is, how are these rates fixed and who does it? How are these numbers 19, 39, 44 etc derived, it's always 1Re less. With around 4-8 collection center in each booth  and with around 60,000 - 1 lakh vehicles moving along the NH4 on an average, each booth would be earning around 60 to 1 lakh rupees extra. Now how much would Cadbury charge me for each eclairs if I promise to sell around 60,000 to 1 lakh chocolates from each booth ?  I guess it should not be more than 30-40 paise per chocolate. That is around 60-70 thousand rupees a day for each toll booth.

If this thing is knowingly or unknowingly happening across the entire country across all highways then this should be the next big potential highway chocolate scam!