Per Diem For Truck Driver Need Help

in a nutshell this is my situation.......i drive locally for a company, which means i have no overnight expenditures. that being said, i am now receiving per diem. per the federal publication 463 i am not qualified for this. the company states they are perfectly within their "legal" right to pay me per diem regardless of what i think. i further looked into my payroll stubb and from what i can see what they claim they are doing and what is really going on i am not receiving it at all. my pay stub looks like this....not actually dollar amounts but accurate as a representation.

gross earnings 47hrs @ 12.50 587.50
per diem +104.00
per diem deductions -104.00

then comes taxes and finally net, and the net affect of the per diem is 0.00 so why is it there anyway,,,not what i understood per diem as..seems to me they are saying they paid me this but then took it right back......so they can take a huge tax break at the end of the year at my expense,,,,,,

any help would be grealtly appreciated

The result is a net zero so I don't see how they would get a tax break.