About 12 months ago I bought a Galaxy A21s phone at Au Post. I told the salesperson that the phone I am buying must be unlocked because I need to use other sim cards in traveling abroad. I was assured that the phone was unlocked.Now I am overseas but I am unable to use a non-Telstra sim in the phone because Telststa took it up on themselves to lock my phone without telling me. I contacted them and they say it will cost $25 to unlock the phone But they also told me that they will not unlock my phone while I am overseas. I am now unable to receive messages and calls even on phone. I can't open my main Gmail because I can't receive confirmation from Google nor can I get a one-time password from my bank or other SMS confirmations that I need to approve. Telstra blatantly refuses to solve my locked phone problems. This is causing me a lot of inconvenience and distress.Please make sure that your phone is unlocked if going overseas even if you bought an unlocked phone. I will look at taking this up with the Ombudsman on my return to Australia.Peter Drackett