Firstly, I honestly think your electricity bill is TOO HIGH!!! You need to look at putting in measures to bring it down, unless of course your business is electricity intensive and you work from home. But as a normal home user it should be no more than $50 (I'm hoping you've just added an extra zero there and your figure is meant to read $100 - one hundred dollars, and NOT one thousand as it appears).
In that regard, I do know that one can have more than one electricity prepaid meter at their house (this has usually been the case where there is a cottage in the yard along with the main house). This being said, I suggest you visit ZESA Wayne Street, Harare (or your nearest ZESA regional office and make enquiries there). Or hopefully, someone from ZESA sees this post and knows any better and can advise.