How to replace replace special character but not & in SQL SERVER

To achieve the desired results where "Q&A" remains as "Q&A" and "Q & A" is transformed into "Q And A," we need to adjust your SQL code slightly to avoid replacing the ampersand in "Q&A." 

DECLARE @RawDescription varchar(255) ='Q&A'
-- First, handle the replacement of ' & ' with ' And '
SET @RawDescription = REPLACE(@RawDescription, ' & ', ' And ') 

-- Then, we will replace any unwanted characters while preserving the '&' character
WHILE PATINDEX('%[^ ''0-9A-Za-z&]%', @RawDescription) > 0
BEGIN
    IF SUBSTRING(@RawDescription, PATINDEX('%[^ ''0-9A-Za-z&]%', @RawDescription), 1) = '-'
    BEGIN
        SET @RawDescription = TRIM(REPLACE(@RawDescription, SUBSTRING(@RawDescription, PATINDEX('%[^ ''0-9A-Za-z&]%', @RawDescription), 1), ' '))
    END
    ELSE
    BEGIN
        SET @RawDescription = TRIM(REPLACE(@RawDescription, SUBSTRING(@RawDescription, PATINDEX('%[^ ''0-9A-Za-z&]%', @RawDescription), 1), ''))
    END
END

-- Remove extra spaces
WHILE CHARINDEX('  ', @RawDescription) > 0
BEGIN
    SET @RawDescription = REPLACE(@RawDescription, '  ', ' ')
END

SELECT @RawDescription