Wound of TURBT site isn't healing even after 2.5 years

I am from Bangladesh..please show me a way how it can be managed.

Hi
My mother 55 years old Non diabetic Hypertensive,was undergone TURBT 2.5 years ago.Her histopathological report was High grade non invasive stage 2 TCC.
She was given 6 cycle of intravesical mitomycin started afted 10 days of TURBT. after 1 month she was adviced 6 cycle of intravesical BCG.She only took 4 dose of BCG as she didnt able to tolerate its burning sensetion.Her PET CT scan report was normal.

After 3 months she was undergone followup cystoscopy.There werent any tumor but there was an ulcer at the TURBT site.

Then she was undergone Follow up cystoscopy totall 4 times T 6 months apart. Every time the finding was an NON HEALING ulcer at TURBT site. Her last followup cystoscopy was on january 2020.this time doctor took ulcer tissue for histopathology.The report showed extensively ulcerated tissue with atypia but no malignant cell.
Everytime her other repors were normal including Urine RE. Doctor told us to do Re cystoscopy again after 6 months.

Why her wound isnt healing atall ever after 2.5 years?
What should we do now?