Is there any case that the new sensor is also faulty? It is not uncommon to buy new parts which are not fit for purpose. I was trapped like that with a garage doing a brakes service. He did not want to admit that the parts he fitted were not good enough. I paid another garage to put the car right but I lost out the money I paid the first garage as he was insisting that the parts were right even after the repair from the second garage.
Also, did you do some kind of reset when you fitted the new sensor? Online search suggests that you need to reset the values already learned and needs to go back to the OEM setting. The suggestion is to remove the battery and leave it disconnected for 10 minutes. The service manual suggests that after disconnecting the battery for 1 minute, it is enough to work on sensitive parts like airbags. So maybe the generic 10 minutes is good enough.
If you have done the diagnosis and repair at a garage, you should try to reason with them but I know how bad that can turn out. If you cannot reason with them and cannot work on the car, try another garage for a second opinion. If you have done all the work alone, try disconnecting the battery for a start.