Do i have to pay bill?

While the company should have done a better job explaining to you what was and was not included in your plan, if you were provided with the written terms of your plan, including what was and was not included, and didn't read it or didn't understand it, I don't see how you wouldn't be responsible.

I suppose if the company specifically misrepresented to you that nights and weekends were included, when they were not (that doesn't seem to be the case from the facts you present), you would have a case, but the company just putting you on a plan bad for your calling habits and your failure to monitor your calling doesn't rise to a cause of action.

Disclaimer: This answer is provided as a public service and as a general response to a general question, it is not meant, and should not be relied upon as specific legal advice, nor does it create an attorney-client relationship.