******* meter services company

I moved out of my flat on the 23rd of January. The invoice for January was R230.30. I ensured that I turn everything off including the main switch. The entire February the flat was vacant and I put in a notice on the 21st as I had someone interested in renting my flat by March 1st. I had the keys to my flat the whole time and it was locked so I can't say that there was someone there. To my horror, I received an sms stating that I owe R2171.75. how is it possible that an unoccupied flat accumulates so much? Never had I had a bill over R2000 while I was staying at my flat but when I moved out it is more than that? How do I get this rectified because even the meters are locked at all times at the complex, only the guy reading them has access to them? I enquired and it has been a week without them getting back to me?only a ticket was opened.