That is pretty much the case these days when wants to change the routing that one has to cancel and repurchase the ticket at the current fare. Many do not use an OTA because they can have additional costs over booking directly with a specific airline.

Further, the increase in price maybe due to the routing. While one might think ROM->LAX would be cheaper than BRI->ROM->LAX but that is not always the case. Which is more or less the case of hidden city ticketing. Do search on the these routings to verify.

In the end not a scam but how things work today.