Sorry, but it is NOT fraud.
PP, What company do you work for, and what is it that you do for them? And how long ago, lol. Because in the last couple of decades now, the insurance company can NOT dictate that choice. Used to be back in the old days they wouldn't even pay you, only the repair shop directly (and they often had it done at a repair shop they had a relationship with and it didn't cost nearly as much as you would pay privately, etc.....but then again, less than honest agents/companies would also take short cuts with the repairs, blah blah blah. But a lot has changed in the decades since then, lol).
Your insurance company will tell you to get 2 or 3 quotes (some ask for 2 some ask for 3, so that depends on your insurance company). You submit those quotes to them and they will pay the lowest one. Period. They can RECOMMEND places to go (since most people have no clue where to go), but they can't force you to do so. There is certification for repair centers and you do have to choose one that has the right certification. But that's as far as they can go for requirements. You can then get the work done or not. It's your choice. If you would prefer to have the work done at the more expensive place, then you pay the difference. Of course, the wiser move would be to get more quotes done until you find ones higher than the place you want to go. It doesn't cost anything but time to get estimates, so feel free to get a dozen if you want (though that's a LOT of time, as typically even small damage can take 30-60 minutes once they get to you...waiting can be a bit as well). And no, that's not fraud either, because you have your choice of where to take your car (though it must be a licensed facility, blah blah blah, not Joe down the street or Dad). If you choose to shop around, that's your choice.
Now....the above person was sorta right in that if you don't have the work done, and the car is hit again on that side the insurance company will NOT pay to have that portion fixed. In other words, if the second strike is a foot away, they're going to deny the claim for the older part and sometimes that means the quote will be very low for the second strike because they can only estimate for that part and cannot replace the other part. For example....the first hit is on the rear bumper. The repairs would have been less expensive than replacing the part because the damage is minimal. It's ONE piece of fiberglass (or if it's an older car it might actual be metal, lol). You opt to keep the settlement and not do the repairs. Later the car is hit in almost the same place. The second hit combined with the first makes the piece unrepairable and it now needs to be replaced instead. The insurance company may opt to deny the claim because had the first repair been done then this second repair would have been less expensive because it wouldn't need replacement. Follow me? A good attorney, however, can often argue that out of denial and into a lower payment, lol. Did that quite often, lol.
Fraud would be if you told the shop that you took the car for an estimate to write it up with some padding, so that you could get extra cash. Or to include, but not write down, the repair for the other side of the car that you damaged last year and didn't report. Or, "If you make this estimate $100 more I'll give you half of that". THAT is fraud.
THe law says that you have the right to have the vehicle repaired at your choice of place. The insurance company has the right to require your estimates be at places they approve (meaning certified repair) and pay you the lesser or the estimates. Now, if you turn in your estimates and they feel they're all too high, they also have the right to an "independent estimate" meaning one at a shop of their choosing, and again, it must be certified etc, but it could come in lower than yours and that's all they'll pay.
Ok, the reality is a bit more complicated and there are lots of variables....but the long and short.....yes, you can pocket the money if you choose not to have the repairs done.