Most definitely my next car will not be a Nissan. DPF Problems

Most definitely my next car will not be a Nissan. My stop start warning comes on and not long after that engine light 1 and engine light 2 then limp mode, DPF then when i take it in to Nash Nissan they tell me... drive the car once a week on the highway They also say I must drive the car 4000rpm and 120kph for 15min if the warning comes on They also said I must keep the rpm high as a diesel motor needs high rpm. I also get told that i am very lucky that they don't charge me labour every time the DPF block up as mercedes-benz drivers must pay for that I followed the advice but my fuel consumption went from 7.5 to 9.2 L/100km Its ridicules, and after changing my driving style it still does it. My warning lights come on, on a monthly basis. and also goes in once a month 2015 1.6d Nissan xtrail T32 70 000km (still under warranty)