Narrative:

Departed bkw for crw. Talking to crw approach. Initial altitude 6000 ft, was then cleared to 5000 ft. At approximately 17 mi from meeky, I was cleared from 5000 ft to 4000 ft. As I reached 4000 ft approach came on and said aircraft X cleared to 2600 ft. I read back cleared to 2600 ft. As I approached 3500 ft approach came on asking what I was cleared to. I stated 2600 ft and he said negative, climb maintain 4000 ft. I climbed back to 4000 ft and continued to charleston for the ILS runway 23. The rest of the approach was uneventful. He had also stated the 2600 ft had been for aircraft Y -- airplane on the approach in front of me. I think the problem arose because the controller was working multiple frequencys and as having a hard time keeping up with the traffic. When he asked me what altitude I had been cleared to, he stated that the 2600 ft cleared had been for an aircraft by the call sign of abcd. I was unaware of that because we were on separate frequencys. What makes me also think he was having a hard time keeping up was the fact that different aircraft were having to call him multiple times to get a hold of the controller. So even though I called back cleared to 2600 ft, he never heard me. The way I would handle a situation like this next time would be to maintain the higher of the two altitudes and confirm that I was cleared to the lower altitude.

Related reports:

Google
 

Original NASA ASRS Text

Title: C310 PLT WAS GIVEN AN ALT CLRNC MEANT FOR ANOTHER ACFT ON A DIFFERENT FREQ IN CRW CLASS E.

Narrative: DEPARTED BKW FOR CRW. TALKING TO CRW APCH. INITIAL ALT 6000 FT, WAS THEN CLRED TO 5000 FT. AT APPROX 17 MI FROM MEEKY, I WAS CLRED FROM 5000 FT TO 4000 FT. AS I REACHED 4000 FT APCH CAME ON AND SAID ACFT X CLRED TO 2600 FT. I READ BACK CLRED TO 2600 FT. AS I APCHED 3500 FT APCH CAME ON ASKING WHAT I WAS CLRED TO. I STATED 2600 FT AND HE SAID NEGATIVE, CLB MAINTAIN 4000 FT. I CLBED BACK TO 4000 FT AND CONTINUED TO CHARLESTON FOR THE ILS RWY 23. THE REST OF THE APCH WAS UNEVENTFUL. HE HAD ALSO STATED THE 2600 FT HAD BEEN FOR ACFT Y -- AIRPLANE ON THE APCH IN FRONT OF ME. I THINK THE PROB AROSE BECAUSE THE CTLR WAS WORKING MULTIPLE FREQS AND AS HAVING A HARD TIME KEEPING UP WITH THE TFC. WHEN HE ASKED ME WHAT ALT I HAD BEEN CLRED TO, HE STATED THAT THE 2600 FT CLRED HAD BEEN FOR AN ACFT BY THE CALL SIGN OF ABCD. I WAS UNAWARE OF THAT BECAUSE WE WERE ON SEPARATE FREQS. WHAT MAKES ME ALSO THINK HE WAS HAVING A HARD TIME KEEPING UP WAS THE FACT THAT DIFFERENT ACFT WERE HAVING TO CALL HIM MULTIPLE TIMES TO GET A HOLD OF THE CTLR. SO EVEN THOUGH I CALLED BACK CLRED TO 2600 FT, HE NEVER HEARD ME. THE WAY I WOULD HANDLE A SIT LIKE THIS NEXT TIME WOULD BE TO MAINTAIN THE HIGHER OF THE TWO ALTS AND CONFIRM THAT I WAS CLRED TO THE LOWER ALT.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.