Nick is right. The next error is the else should be else if (you currently have a boolean expression in your else which makes no sense). Here is what it should be
ELSE IF(@Trans_type = 'subscr_cancel')
BEGIN
SET @tmpType = 'basic'
END
You currently have the following (which is wrong):
ELSE(@Trans_type = 'subscr_cancel')
BEGIN
SET @tmpType = 'basic'
END
Here's a tip for the future- double click on the error and SQL Server management Studio will go to the line where the error resides. If you think SQL Server gives cryptic errors (which I don't think it does), then you haven't worked with Oracle!