Businesses should not be calling repeatedly without leaving a message. Very unprofessional. But, why should I expect anything else.
Just had Optimum installed yesterday. This number called my house 4 times today, not once leaving a message. If they want to know how my install went, why not leave a message?
Yes, the below comment about cablevision/optimum appointment confirmation is definitely the reason why they're calling you.
Cablevision / Optimum Online appointment confirmation
Recieved a phone call today from this number, no message left.