It seems to be hit & miss with them. If they have your order in stock they will send it out to you. If they don't, they will set about sourcing it from suppliers and that takes as long as it takes.
I waited over three weeks for a small order and they ignored all attempts to communicate until after it had been delivered.
Drop shipping is the new business model
(I stopped using Allgerman for the same reason.)
Every twaaat and their dog seems to do that nowadays...
For example, I ordered six can of my favourite upholstery cleaner ten days ago. Order confirmed, get an email on the Friday confirming shipping with a delivery date of last Monday/Tuesday. Obviously it didn't turn up, so on Thursday I rang them... "still processing orders from 23rd March... Don't know if we have it in stock, so I will get it shipped here from our Sheffield depot. And will forward it on when it gets here."
I understand that places are short staffed and that delivery times are a bit off at the moment, but if you don't stock something, you shouldn't be allowed to advertise it.
So, today, I need to go to Halfords to buy it at 50% more just so that I can start to get stuff done ready for replacement bits to get the car running.
ATP are cheap, and it isn't unreasonable that this affects their service standards, but at least you know that you get what you pay for. And I would rather this than paying through the nose for shit/unhelpful service from franchises.