The delivery times seem to vary anywhere from around 4 - 22 weeks. I think it all depends on how many add ons you get and if you are taking over someone else cancelled order. Give it another week or two then call SEAT customer services for a build week. You will need your order number from dealer for this.
UK dealers have been told to give lead times of 23 weeks to customers by Seat UK. This does not mean that it will take that long but, 7 weeks from order to delivery does seem unlikely. But, you never know!