PIP

Question , I know you can not claim pip if you are over pension age and if you are getting Attendance allowance ,but when you look at eligibility it start's usually which would indicate there could be exemptions to the rule ,

My situation is my wife was getting higher rate pip when she passed away in December, I never applied myself although disabled for the past 10 years as we were using her motability car which I no longer have but need . Motability said there may be a case for a retrospective claim as I have been disabled for so long myself but when I spoke to DWP they just shut me down straight away which is much what I excepted , they are not really forthcoming to help , but I wanted to know if anyone actually knows 100% .

Thank You