False advertising

Tyme bank is a ****, they say they give 10% interest on 6 months fixed deposit while it is in fact 5% that they give in May when I opened my fixed deposit and complained about that, someone from their bank called me to say I will get my 10% at the end of my investment term but we'll it has paid just the 5%, the need to change their false advertising or pay me my 10%, because if interest is indeed 10% then I'm not supposed to be getting 1500 from fixing 30 000, I'm suppose to get 3000 in interest.