Is it normal for British Gas to take 7-10 working days to get parts for a boiler?

I have water running down my wall in the kitchen from the back of my boiler on the wall and have to put a towel on the floor in there to soak up the wet. I have to wait for 7-10 working days before I can get this resolved. The engineer said he needed to order 3 parts for 3 seals that had worn.