I agree with something someone else said, that no slogan is better than a bad slogan.
My 2 cents: I'm not a marketing guy, I don't even know what your company is called, and if it can be incorporated into the slogan, but you HAVE to keep it short.
I too, read your slogan as "we don't want your business" and laughed cause I thought it was a joke, but then read on and was like "wait what? it's not a joke?"
shorter slogan. What do you do? what is your company name? what do you want to present to your customer? what are your core values?
as a graphic designer / starting up signmaker, I've developed plenty of designs for corporate identity, a slogan is always welcome, IF it's a good one.
something like (and these are probably already taken, I have not done research)
Company y: Signs done right.
Company y: Signs for life.
Company y: Digital Media For the masses (meh)
company y: sign experts
it's not so much a slogan, as it is a visual descriptor.
if your company is called something that can be fit into the slogan, thats good too
Signway: There's the Signway, then there's the wrong way. (long and meh)
anyways, hope you find one!