Why is my fuel hand reading full all the time after installing new pump on 1999 Chevrolet Suburban 1500

I got a new fuel pump installed now my fuel needle is reading full all the time now the garage is telling me my gauge is messed up but it didn't mess up till afterthe new pump was installed

Asked by for the 1999 Chevrolet Suburban 1500
2 answers
sounds like they have a grounded wire or the sending unit float is stuck on yhe wires, this has happened to us b4.return and explain nicely and ask if they can recheck by doing a gauge sweep with a tech 2 scanner
sounds like the shop may have crossed the sender wire when they replace the fuel pump pig-tail or the bent the float