Should I be paid for being on call

If you are an exempt employee, then you can be made to work as many hours as your employee sse fit. That is unless working this time unpaid violates the terms of a union agreement or employment contract. Otherwise, you are not owed any additional compensation. As an "at will" employee your options are to comply and work these hours unpaid, complain and risk termination or quit.
If, on the other hand, you are non-exempt, then you may be entitled to pay. Not all on call hours are eligible for additional pay. Compensable on call time is determined by looking at various factors including: the frequency of the calls; what the fixed time limit for response is (e.g. 30 minutes); if there are geographic restrictions placed on the employee; whether the employee can trade their on-call responsibilities with another co-worker; and if, and to what extent, the employee engages in personal activities during such periods (e.g. not being permitted to consume alcoholic beverages). If it is determined that the restrictions are too limited, then it will be considered time for which the employee must be paid. In your case, you would have appear to have a legitimate claim for pay, but again, only if you are non-exempt. 
Typically a manager is exempt but an hourly worker is non-exempt, and you are both. So to determine your actual status you can check with your state's department of labor or the federal DOL website. You can also consult directly with an employment law attorney in your area.