Unfortunately, your tale of woe doesn't surprise me at all!... It may be worth contacting Sea & Sea direct? Their base in Devon has always been really helpful....
I tried to buy a zoom gear at the weekend and phoned one of the, if not the biggest underwater camera stores in the UK to buy one. I got an answer that the other shop is closed and I will get them to call you on monday. The guy in the London shop could not even tell me if the other branch had it in stock. Anyway I had a look on their website and the website is a bit of a joke as well, they have their website and then you can enter their online store through their website. Trouble is they only have about a quarter of the items for sale on their online shop. Obviously not happy with this I wrote and explained that their website is rather poor. Today I got a response.
31109 Canon EF 17-40mm F4L USM Zoom Gear GBP 106.99 inc. VAT
Unfortunately we do not have the item in stock and as it is a sea and
sea item it may take a very
long time to come in possibly about 6 - 8 weeks
If you have any other questions please feel free to ask
Wait 6 - 8 weeks for a bloody zoom gear. THATS WHY I DONT SHOP IN THE UK