No, I think calls to Mobiboo geographical numbers are not barred on T-Mobile and Hutchison 3G as Mobiboo would not be charging a high termination rate.
I would suggest that you contact T-Mobile or 3 customer services.
T-Mobile:
150 from a T-Mobile phone or 0845-412-5000
Hutchison 3G:
333 from 3-Mobile or 0870-7330-333
customer.services@3mail.co.uk