Make sure you're still getting the 3 discounts.

I had the 2 discounts and TopCashBack 10%. Nokia wrote to me asking me to call the shop, but when I didn't, after a few days they called me, and told me my order would be cancelled unless I agreed to a new order, because they weren't intending to accept multiple discount codes.

They gave some dubious excuse about the product number being changed so needing a new order.

Anyway, they let me keep the 2 discounts but instead of compounding them, the new order just added them to make 30% off, which was £10 lower than my previous order :-) But I lost the TopCashBack discount due to the new order - the Nokia sales rep hadn't heard of that, but checked and confirmed that was the only option, and wouldn't reduce the price any further to compensate.

Point is: They made it clear they were going to cancel the original order if I didn't talk with them to make a new order. I'd advise calling them to confirm your order.