Finally figured out. I had to go to the shop in person and the person made a call to find out what happened.

I had recharged magenta L with 15 € on Wednesday. Immediately i got a message in German at 1057, which was translated by Google as recharged for 15 euros.  I made my first call at 11:00. But apparently, the message I received was not the actual confirmation. So, my calls were being charged. I didn't know this. Nor did I know I had to wait up to 1 h to receive the "actual confirmation" to start using the 2 GB data and 300 Min. I started asking about this since Thursday and have been going around in circles not knowing what was happening. Because no one would speak to me...chat/hotlines. Meanwhile,  I have also been "automatically signed on" to 50 MB per day at 1,95€. I didn't sign up for this or agree to this. Therefore, T-Mobile has been charging my calls and internet, and "could not recharge Magenta L" because there was "not enough balance".

I'm sorry, but this seems not right or fair. 

I still haven't received any call from your personnel.

I couldn't get through to any of your help line by chat, hotlines and the English services how much ever I tried as a two-month resident in this country. With no German skills. Can't speak the language in 2 months....

It's not that I don't want to learn the language or am not putting in effort as a single person, moved in to Germany from Japan during a pandemic, while trying to get settled in a new country, working full time....minimum 45-50 h a week. Besides, I've tried to integrate in other countries...like japan (lived there for 8 years, learnt the language from scratch). 

But this seems to be not just language issue, but strategic miscommunication and lack of service. Or empathy  or care. I hope t mobile sees that I have tried my best....as a customer to get in touch to try  to understand the issue....

I don't think I want to continue to be your customer. Even though the shop assistant was polite and helpful. But the entire system seems very unhelpful, also giving the vibes of severe lack of accountability to customers.

I had to recharge extra 7 euros to once again qualify for Magenta L. 

I tried your prepaid to test waters...if I want a long-term contract. Nope.

Hi @Carolin L. 

Just checked my account on the website.

I dont think your top-up of 15 euros has worked yet.

My account says ~ 16 euros [i.e., from my 15 euro paypal top up on 8th Dec MINUS amount lost on calls + surfing PLUS 7 Euro (cash) top up today at the store] . Valid for about a bit more than 3 weeks.

Perhaps, the re-charge from you will take time till Monday to be credited? 

Will wait and see. 

Thanks again for trying to help. Hope it works out.

@Raj 

Thanks for the honest words.

Many greetings

juergen3004