London Oyster- free £5 credit

starlit_2

I activated auto top up at a DLR station even though I wasn't making a DLR journey, and it charged me £4.00. I rang Oyster and after the rather cocky 'assistant' getting confused and contradicting himself for a while, he refunded the £4.00 to my credit card.
I managed to get the £5.00 joining up credit too.
I thought that this would be added to my Oystercard, but it's actually deducted from the payment. So I got £10.00 credit on my Oystercard, but only £5.00 was taken from my credit card.
It all seems to have worked out, and I'm £5.00 up on the deal! (Or £4.00 if you count the fact that last week I was charged £1.00 more than their website implied that I would be.)

I wasn't aware of this offer at all until it was posted here, so many thanks to the original poster.