Network not switching from 3G to 4G

I recieved an sms from vodacom to say I can. Switch to 4G so I called customer care they said the sent the setting to my phone and I must switch off my phone and switch it on after 15minutes which I did and they showed me where to go and my phone will move from 3G to 4G but it didnt so last night I went to the vodacom store in the Glen the one opposite dischem and they tried to check why it wasn't changing and I stead offered me to do a sim swap to resolve the problem which I did and had to pay plus minus R70 but I did as I was told to swap the sim card when the other stops working but now my phone is still on 3G and the caller I'd is not working and I paid R9 for it to work