Suspect a robocaller----calls several times a day at all hours, disregarding the fact that the line is for business and personal use. Never leaves a message. When call is returned, there is never an answer or recorded announcement or even a ring----just a fast busy signal.  Frequent calls eg 3 times in 24 hours. Started abruptly.

Has called six time sin the past 48 hours. No message. Called with an out of state cell with different carrier, and got the usual T-mobile tones and the "Welcome to T-Mobile" followed by the standard menu. This may be a line the company uses to sell services. If it is the may be losing a customer.

Suspect a robocaller----calls several times a day at all hours, disregarding the fact that the line is for business and personal use. Never leaves a message. When call is returned, there is never an answer or recorded announcement or even a ring----just a fast busy signal.  Frequent calls eg 3 times in 24 hours. Started abruptly.

Unknown number keeps calling and when called back I get no ring message only busy signal

receiving several calls from this number over the last few days.