Re: just lately my daily budget has been used up before the end of the day yet we are getting no bus
From your question I presume that you are spending your daily budget, but the visits fail to generate any revenue for your business.
There are so many reasons for this, starting from wrong keyword selection, match type selection and bad ad text.
Most of the time generic keywords in broad match without any negative keywords are the main culprits.
Please go through some of the tips in the below links, which may help you to improve your campaign performance.
Build a Good Keyword list.
Selecting a keyword match type
Creating effective text ads
Hope this helps,