Mondo and MTN

I took out a MTN contract, via Mondo. The DSV courier comes. My left thumb doesn’t want to scan on their device. I always experience problems with my fingerprints. Last week I informed Mondo that I seldom pass it. Now I phone them and basically nobody can assist me at MTN or Mondo.Their policies are not working for everyone. In this day and age, surely there should be flexibility regarding biometrics.