I have some ideas how to improve the service and network.
1. I recently noticed that the prices of abonament went up (or at least the discounts you give on new abonament are smaller)- after reading couple of articles that Tmobile will be price cutter- I am surprised to hear that.
2. Tmobile App- is there an english version? You can set up network messages in english so next should be english language in Tmobile App
3. Abonaments- I like Stel Samen & Stel bij as they are getting better and better. I am still missing the type of abonament that Tmobile USA offers- with internet and calls all over the world- for around 80 euro per month you have unlimited internet all over the world. In Tmobile Nl- for 90 euro extra unlimited internet in The netherlands plus 2 GB in EU
4. WiFi calling- any update?
5. VoLTE- any update on this?
6. Tmobile Roze Loper App- I would like to join:)
7. Transfering number- I suggest to make an offer when people sign new contract with you they can use temporary number for free until their number is transferred or make a speciall offer for people transferring numbers- lets say 2 months for free and no activation fee.