I bought minecraft
Your account is not premium (not paid-for). If you think that you bought it from Mojang, then you need to contact the support at Mojang.
If you didn't buy it from Mojang (or via an official pre-paid gift-card), then you have probably been scammed and will need to buy an account from an official source.
Either way, there's nothing that mcme will do to allow non-premium accounts to join.