Signing the Strata Agency Agreement for a multiple lots strata plan

Dear experties,

We (most of the owners) are in a deep misery. We live in a 6 unit block. 3 of the owners are in the EC, and one of us 3 owns 2 lots (commercial lots, used to be one lot only, but he subdivided the lot into two). I will use 'C', for later on in the paragraph. We were in a stage of changing the strata agency, which was also recommended by C. As all other owners knew very little of strata since the beginning when we moved to these brand new properties. However as far as I remember, the old strata agent explained to us during the AGM about all the elements, terms, registrations etc of the agreement before we signing it by two owners. C and another residential owner A, I am B in this case. 

However while A & B are still wondering when to sign the agreement, the new strata agent told us that the agreement was sign and sealed. But signed by whom? We are are sure all the residential owners didn't sign and agreement nor been given the agreement for a glance. Later we found out the agreement was only signed by C and the new strata agent then seal. This is very unfair don't you reckon? Does the new agent have the power to affix the seal when only one of the 6 owners signed the agreement? Shouldn't it be signed by at least 2 owners or EC by the strata Act section 238? The agreement didn't state a valid term, but only state that to terminate the agreement we need to give 36 MONTHS notice by majority of the owner votes. If we have been given to see the agreement at the first place, I am sure none of the residential owners would agree the term. As who would fix to a new agent for such a long time without even experiencing their services. There's no doubt something going on between C and the new agent. 

My question is: is the agreement valid? And however are we suppose to do to at least have it fixed. We are all paying the agent only only C! And obviously the agent is not professional enough to be a fair and square one. Please help….