I wanted to know is it possible for the government to deny or reject your refund?

[xmasbaby0]

Of course it is possible.   If there is something that is not okay with your e-file the e-file can be rejected.   Or if the IRS accepts your return and finds something wrong with it, they can reduce your refund or not send you any refund at all depending on the mistake.   Or it is possible for them to discover that instead of getting a refund you owe and need to pay.