I contacted American Red Cross Blood Services about these calls - I have received over 100 calls from this number. They responded professionally, courteously, and appropriately, confirming that: this is indeed one of their numbers, that they do not pull numbers from a phone book or purchased lists, and they use only numbers that donors have provided to them. They said that if you do not wish to receive calls from them, please contact them at 1-855-210-1278 or at
[email protected] and ask to have your number removed from their list.