Are you living in a villa partitioned building? IF so, that'll explain it. The entire villa (partitioned into four or six parts) will be having only a single metre. When four or six families use water and electricity, and it is calculated by a single metre, it would come to a large number.

In Qatar, they bill you by usage. For example, they may have a tariff, say QR.50 for one unit if your consumption is below 100 units. They will charge you QR.80 for units between 100 and 20. The rate may be QR1.20 for every unit between 200 and 300. It goes on like that, increasing each time the limit is breached.

When there are more families using the resources using the same metre, there's every chance that you use up 800 to 1000 units a month, at least. This is the reason why you're being billed so highly.

I had the same problem and was paying above 300 each month, although I too was not at home vey often. I changed houses, to Barwa, and my highest bill since then has been QR123.

Demand your landlord to change the system to an individual metre or move out ASAP. I hope you do something soon, or you'll end up paying through your nose. All the best!