Not receiving updates in my mobile device. Mobile with Yoigo company (Spain)

I'm not able to receive twitters on my mobile phone anymore. It's the same with my mother mobile and my boyfriend's. We all have Yoigo mobiles (Spanish company) and I think this is the problem. Maybe they are blocking twitters, because I have just changes to an older number, which is from another company, and twitter goes as perfect as always was.
I have written to twitter help many times and I never have any answer and neither the problems gets solved! Please, try and fox this problem, because we are many people in Spain that have Yoigo and are using twitter every day.
Thanks