I am wondering if the strategy should be changed to "include" those who are doing the wrong thing. They are parking there because there aren't enough spots for them to park elsewhere. They are facing the same problem as you are.
Get someone who has a way with words to get an online petition going that is directed at the council and basically says that there is insufficient parking at Wello point. Use the council and state guidelines in relation to parking requirements in the petition and sign it off as "The Users and Rate Payers of Redlands Council"
Some of the wrong doer's don't have any idea they are in the wrong, some have an idea that it is wrong and take the chance anyway and others that don't care either way. The last group won't change. The others might if they are made aware and there is some where for them to park.
My point is to get them involved and present a united voice to council and then see what they say.
You could also get the local businesses to sign it. They will want more parking. If the users and businesses are wanting the same thing they might listen.