Based on the comments, it appears that the caller is likely making automated calls to check if phone numbers are still active, resulting in a busy signal when called back. The frequency of similar experiences reported by multiple individuals suggests a systematic approach, possibly for telecom maintenance or verification purposes. The fact that callers are unable to get through when calling back, only to receive a busy signal, supports this theory.
It appears that this number is linked to the GUAM Telephone Authority, which may be using it to verify the status of phone numbers.
Similarly, I received a call at 6:36 PM on March 26, 2014, and every attempt to call back has been met with a busy signal.
The experience of receiving a call from this number and getting a busy signal when calling back is a common one.
Multiple attempts to call back have been met with a busy signal, making it difficult to determine the caller's identity.
After missing a call from this number, I've attempted to call back multiple times, only to encounter a busy signal, leaving me wondering who this is and how they obtained my number.
Today, I received a call from this number, which seems to be a familiar experience for many.