light therapy and microdermabrasion are all said to give brilliant results. These have to be done by a clinic and there are quite a few of them about, ask the clinic to show you before and after pictures of their clients so you can see how they compareto other clinic.
There is also a powerful treatment called Isotretinoin, however it has the potential to cause serious side effects such as depression and it will harm an unborn child, so people on it have to have regular neg preg tests, but it also must be said that lots of people have used it with sucess.
So far, i think microdermabrasion over a number of sessions seems to look like the best option, and make sure that any foundations you are using are "non-comodogenic" meaning non pore blocking, as you can have oil free foundations that still manage to block pores.
Make sure you are not using high street foundations, they MUST be from proper brands, such as Lancome, Clinique or Estee Lauder ect. High street stuff always give me acne.
Also, make sure you use an oil free moisturiser before foundation, as your skin may be overcompensating if youre not hydrating it. Try Aquafit by Lancome, or for cheaper brands NO7, boots botanics or garnier blemish care brands.
www.harleymedical.co.uk/non-surgical-solutions/medical-microdermabrasion/
http://www.microdermabrasioninfo4u.com/microde rmabrasion/microdermabrasion-acne-scar.php
www.lorealparis.co.uk (loreal do one you can buy in boots/superdrug ect) but its NOT effective as a clinic as you have to rub this on with water whereas the clinic uses special equipment. Microdermabrasion is also not chemically and intrusive like a glycolic peel, which has not really been held up as a great acne treatment.