The BS6 OEM relays are known to be of low quality. Especially annoying is the fuel pump relays because if faulty it can lead to all kinds of funny symptoms during driving.
Here are some alternatives with better quality:
Roots RWCR5A
Bosch 0332201107 Changeover Micro Relays - 5 Pins, 12 V, 30/10 A
Hella part number 4RD 965 453-04
Here are some alternatives with better quality:
Roots RWCR5A
Bosch 0332201107 Changeover Micro Relays - 5 Pins, 12 V, 30/10 A
Hella part number 4RD 965 453-04