Tracker knows my phone number better than I do!

I am paying a whack to Tracker every month but I have a horrible feeling they will not be there for me if- God forbid - I really need them. Why do I say this? Because they do not have my contact details so will not be able to get hold of me. Yep, those clever folks at Tracker know my phone number better than I do, and when I try entering it on their app they tell me it is ‘invalid’, never mind that it has been my number for the last 17 years! Without a “valid” phone number they also refuse to accept my email address, so when the day comes that my car is ****** or I am hijacked they will be unable to contact me. Makes me wonder what I am paying for every month. I have tried uninstalling and re-installing the app, I have tried Android and Apple versions of the app, but the problem stays the same and even extends to their website. So much for customer care.