my automatic gearbox?

i recently spent £1,380 on my peugeot 406 hdi automatic.rebuilding the gearbox.when i got the car back after afew days it giving worse problem then before.i took it back to the garage told me to drive in snow mode for one day which i did.is this normal procedure after spending so much the the gear was not functioning properly.now it seems to be working fine.can u plz tell me what work he carried out rebuilding the gear.abs brake defective is appearing all the time now.plz tell if the garage did anything when repairing the gerabox.and how long can expect trouble free gaerbox.thanks