Do a better test of the wiring first before condemning the switch :

1. Pull back the boot of the pressure switch to expose the wiring so you can identify the colours.

2. Using a short piece of wire, join the brown/black and brown wires. This simulates the operation of the pressure switch, which closes the contact between these 2 terminals.

If the pump works, then it would seem to indicate that the pressure switch has indeed had it. If the pump doesn't work, then it isn't the switch, but something else.