Service Deception

I took a truck into the service bay today. I was given an estimate of $200.00 until they were able to determine the cause of the check engine light. Once they determined what it was, I felt their price was excessive, so I went to pick up my truck. I was then informed that it would be a $95 charge due to the diagnostic test they had to run. Not once was I informed of this fee. The service writer only told me of the $200 estimate. We had purchased two previous trucks there and got the service manager to agree to come down to $45, only after a lengthy discussion. We will NEVER visit that store again and will not recommend visiting it.