Volvo Xc 90 D5 Built 2016 Internet Problems

Hello together! I have a problem with my elk (XC 90, built in 2016): We bought a Volvo XC 90 last year and have been having problems with the Internet since then.The car has a modem where we have a data card of O2 inside.Wifi works without any problems,so everyone can access it.I have read that the car can also download apps,such as Spotify.But that doesn’t work with us.Since I have another warranty, I have visited a Volvo workshop and after about half an hour I was told that a control unit was broken.That’s what they replaced,but in the end it didn’t work.Since then, the two other control units, the cable set and the multifunction antenna (costs are over 7,00€!!!Good that I am there with a lawyer) have exchanged.Now the workshop has rendered my car to me and said that everything would be on the data card.The car can only be 3G and my data card can LTE.Can this really be on it?If yes, what can I do?