They call continuely but never leave a message. This goes on & on & on. Who is this?

Was a recording that asked me to press 9.  I did and was told I could get my interest rates lowered on my card with the highest balance and that had a high interest rate.  Had to give up too much information and was not comfortable finishing the transaction.  I then called the credit card company and they said I was able to lower my interest card rates.  That person then transferred me to another department, but I was on hold so long I hung up.  Not sure what to make of all this.