Water meters to complex supply.

[Frequent visitor]

I live in Pretoria/Tshwane. I live in a small complex. There is a water meter just outside the complex. The supply is a single pipe, about 6" diameter (around 15cms). It has two meters on it. For the life of me I cannot see why. On the water bills we are charged two amounts, and from the usage charged for we do not seem to have a situation where one meter shows the higher unit quantities and the other the smaller amounts.
I looked because the charges seem to be higher than other complexes. Which makes me suspicious!

Any techies with any ideas on the subject?

I did ask the customer services people by email, but got no reply.