Xfinity charged incorrect tax for my iphone

I purchased iphone 14 pro max from Xfinity on 18th March 2023.they charge 112.54 as a tax amount. I believed Xfinity and paid the tax ,i thought they would have calculated the tax correctly.

Later when i checked apple portal, the tax should have been 68$. 

Xfinity charged 50$ extra tax.I called Xfinity customer care and talked to them but they kept on saying that it is as per government. When I asked for clarification they just disconnected my call.

If it is as per government then apple is showing a different amount and Xfinity showing different amount? the tax 50$ was incorrectly charged.

Being a loyal customer for Xfinity it is really bad experience and feeling cheated