over charging

I would like to disconnect my dish as I have a technical problem only an installer can fix. I called in as I do all the other times to disconnect my dish until the problem is sorted out which can only be after 2 weeks but they told me I can't disconnect my dish anymore it can only be done on the beginning of the month and not during the month which was surprising cause I have done it before and would only pay for the amount of times I watched the dish but now they cant disconnect it immediately, which means I need to pay the full service for the whole month. I used the dish for the first week of the month only ever since its been off, so they expect me to pay a full month's fee when i only used it for a week and they told me its nothing they can do its how their system work from now on. which I find very unfair.