Same here...got mine today, says 12/99....I joined in 2007...
Looks like everyone's card shows 12/99 as their joining date!
Wasn't it £8.99 a month at first?
It was £9.99 per month and stayed at that price for at least three years if I remember. It then rose to £10.99 then £11.99 then jumped to its current price of £14.99.