esa and disability premiums

hi there,
my partner gets income related esa and was wandering can she claim disability premiums because she has been awarded standard rate pip for both care and mobility.
in september last year her esa was suspended because she cashed a works pension in and got £9475. she then sent proof off to where this money had gone and 6 weeks later her income related esa was reinstated.
anyway we rang dwp to enquire about disability premiums and she filled a form in over the phone and a few weeks later she recieved a letter saying she was not entitled to the premiums because she had received the above lump sum from her pension.
surely they owe her the premiums from the date they awarded her pip in 2017 up to the date they suspended her esa and also since her esa has been reinstated should they not be paying her the disability premiums now.
When they made the decision about the premiums her income related esa had been reinstated so perhaps this decision was wrong, also in the letter it said she could not appeal this decision so shes not bothered contacting the dwp and its now nearly a year since they refused her the premium. just need some advice please.

she lives by herself and because she got her 9000 lump sum from her pension and this was over 5000 they suspend her esa until she provided proof what she had spent the money on to bring it below 5000 which she did and her esa was unsuspended but when she applied for the severe disability premium she was refused because she had got the 9000 lump sum even though at the time of the decision her esa had been reinstated. shes in the support group. should we go to cab and take advice about this matter because at the moment i think the dwp are not paying her what she is entitled to.