ml270 bake squeal

[bigalrhino]

I have a ml270 Se 2004, I've owned the car for 2 years now and im demented with the brake squeal, on the brakes in the last two years I have replaced discs pads + shoes with dealer parts, still squeals, they were fitted by an indie, I took it to the dealer whom checked the brakes and components and said all was OK bar needing a clean which have been done on numerous occasions since, I have also replaced the front pads with e.b.c red ceramic pads which require some 1000 mile bedding in period after which still squealed, I have retained the dealer pads as they were like new which had been chamfered and grooved what do I need to do, I have spent a good few quid on the parts and labour, l have also had numerous brake cleans for free as well thanks to my indie but unfortunately no fix.