Is there some sort of secret club that you need to be in to get a voucher?
Yeah, you have to stop moaning about not getting vouchers before they will send you a voucher.. 😉
Think you just have to stop buying from them so regularly (I know, sounds hard), and if they think you’re going to stop buying from them all together, they will send you a voucher..
Alternatively, try signing up to this site
http://www.topcashback.co.uk/ref/realman/?s=2
If you then go to wiggle (and other sites, like crc) through that site once logged in, you will get money back on all purchases(over 4% from wiggle and crc, over 3% from evans, etc), so you can make quite a bit if you really are spending a lot on there.