Account login doesnt work

Dont know where else to go but there is problem with friends account guess partitionally launcher issue too, in latest launcher it logged him out and since then he cant log back in it keeps sayin wrong email or password which are 100% correct he cant even login on mohjang web neither minecraft web and email for password reset doesnt arrive at all (nor spam or any folder)
he doesnt have payment code anymore since it is few years since he bought an account but his mail which he uses for login was also the one that he uset for first registration and purchase.. this has already happened to him with his other  very old account where he didnt have even email adress and tutorial made for those cases didint work for him and basically told him on support to get new one which he did and he cant use that one now too, but here things get interesting in my PC and launcher which is exact same as his I can log in on his old account (with no email) but not on his newer one while if he tries to log in with old one it also wont let him so I am thinking this may also be issue of a launcher (not even reinstallation helped).. he doenst want to buy 3rd account since 2 are messed up already so hes worried it will happen again