sql - Parsing with substring returning wrong value -

I have this query that at the end of the date (string) attempts to capture the previous 11 characters except the semi-colon is. But when I run the script, it gives value that is not included in the string, and IM stuck for days.

Here is my query

  select the top 2 a.ACCOUNT, A GPSDAT, Sbustring (BSMSMSG, LN (BSMSMSG) - 10, 6) [KM2] to TBGPSC From an APCCAT = BSSSFR Is present in GPRSIN-B (Where to select B from GPRSIN B) SMSFR = a.ACCOUNT and BSMDT between '2014-10-27 14:00:00' and '2014-10-27 14:49: 54 ')  

The result is

The result should be 277511767.8

Can anyone tell me why I am being wrong on this?

You can use the function of SQL like this -

  SELECT TOP 2 a.ACCOUNT, a.GPSDA T Wright (BSMMG, 11) [KM2] from TBGPSC at INNER GPRSIN B AACAT = BSSSFR Where it exists (from where GPRSIN B to BSSSFR = AACCATA and B.S.SS-10-27 14:00 : 00 'and' 2014-10-27 14:49:54 ')