When you call the function you need to specify the SupportstaffID as it is currently it is always 0 and you need to use the return value. If you are not going to use a return value then you should be using a sub rather than a function.

Example
Code:
MyRetunredData=clsSupportStaffQuota_Obj.CalculateQuota(MySupportStaffID)
You also still have another issue where you are setting NewTicket during each pass of the loop. NewTicket will only have the last value assigned which is also something I think you would not be wanting here.