Ordered my pram and car seat 6 months ago to be delivered last week. At the time, paid the deposit and gave them a specific date of delivery. Called them on the delivery date and was told the pram would be there a few days late and the car seat was out of stock so will be there 'sometime in early October'. They never called me to inform me, I had to chase them daily this week. I've now ordered a different car seat instead so I can have it on time.
So either Mamas and Papas are too stupid to realise that when you buy these items it means you're having a baby and therefore likely to be working to a deadline. Or they just expect you to cross your legs until your item is available.
Either way, the deposit is clearly just so they can take your money and offers no guarantee that your item will be available, no matter how far in advance you order and pay for it.
Am currently waiting to see what kind of apology they will offer.