WAMU LOC Decrease

From now on I am just going to call before I even write any checks from my LOC.
I wrote out a check from my WAMU LOC on 3/25. It was deposited at BofA on 4/1 and WAMU bounced it. I called them since my available credit was 43,000 and the check was for 15,000. They said my LOC was decreased on 4/2 therefore I only have $2,000 available.
I spent several hours on the phone yesterday complaining and trying to figure this out as they were saying that it bounced because BofA made a mistake when they submitted it and that was the problem. Well after going back and forth for several hours with both banks, they might let us resubmit and pay it. This was because I refused to accept their story that there was nothing they could do about it.
By the way even the decrease is an error, but they tell me to fix that problem will take at least 10 to 15 days. This LOC is secured by two side-by-side properties, but when they are getting an automated appraisal, it is only for one property and so they automatically did the decrease.
I am definitely changing the LOC to another bank as soon as things get cleared up.
Just an FYI, and venting. Thanks!

You would think they would let you know they decreased it or that there was some kind of error.