Can someone help me to sign up into new devices

Good day,I just wanna know why is TikTok south afry so slow, I've been trying to log in to new devices it keeps on saying wrong devices,or wrong password even if I try to creat new password it doesn't wanna log in,I tried calling help desk still they don't wanna help,they even asked me to tell the when did I join TikTok,how will I remember they should remember since they have systems, I gave up my information to them evething my number username location country except sign up date that one they know,but still they don't wanna help me,I really need their help and I Know they won't respond