SMA ASKED IF WANTED TRANSITION TO LOC THEN LATER TOLD NO COULD NOT HAVE IT. ALTDEV.

Narrative

I WAS FLYING DIRECT TO BECKLEY VOR WHEN ZID ASKED IF I WANTED THE TRANSITION OFF OF BECKLEY TO THE LOC; INTO BLUEFIELD (MERCER COUNTY) ARPT. I HAD TOLD HIM YES; I WOULD TAKE IT. THEN HE CAME BACK ABOUT 5 MINS LATER AND SAID HE COULDN'T GIVE IT; BUT EXPECT RADAR VECTORS TO THE LOC. JUST BEFORE XING THE BECKLEY VOR; HE TOLD ME TO INTERCEPT THE RADIAL 175 DEGS OFF THE VOR AND INTERCEPT THE LOC. AS I WAS XING OVER THE VOR; HE TOLD ME TO DSND DOWN TO 5700 FT MSL. INSTEAD I DSNDED TO 5200 FT MSL; 500 FT BELOW ATC'S REQUEST. I HAD REMEMBERED AS I WAS DSNDING DOWN INTO THE TOP OF THE CLOUDS. AT THAT TIME; I ADDED FULL PWR AND CLBED TO 5700 FT MSL. THE PROBLEM STARTED WHEN ZID CLRED ME FOR THE TRANSITION. I LOOKED DOWN ONTO THE APCH PLATE AND IT SAID 5000 FT MEA FOR THE TRANSITION. THEN HE TOLD ME TO STILL INTERCEPT THE RADIAL FOR THE TRANSITION. ALL ALONG I HAD 5000 FT IN MY HEAD FROM THE APCH PLATE. I FEEL THE PROBLEM WOULD HAVE NEVER AROSE IF ATC WOULDN'T HAVE CLRED ME FOR THE TRANSITION. PLEASE TAKE A LOOK AT THE APCH PLATE ILS 23 INTO BLUEFIELD AND YOU WILL SEE 5000 FT FOR THE MEA OFF OF BECKLEY VOR RADIAL 175 DEGS.