6 months account a lie!!!!!!

My husband opened an account with edgars a few months ago after edgars advertised a 6 months interest free account after the account was opened we realised that it wasn't a 6 months account but 12 months after making it very clear we wanted a 6 month account!today my dad went to open an account in the promenade and the exact same thing happend!he asked them if it's a 6 month account they said yes n bla bla nd everything was fine but then they didn't give him the long slip with the contract on and told him to wait for it and when he did receive it it shows 12 months omw what a con!they then tell him after he see's this on the slip that HE must phone head office oh my woooord!when my husband tried to change his account from 12 to 6 months he was told that it's impossible!why are u advertising lies!