How do you handle a customer who starts yelling at you as soon as they pick up and find out that you are a telemarketer?

As a telemarketer, the best way to deal with any customer is to keep your calm. At times the customer has other things going on and does not want to deal with a telemarketer.

Just keep your calm, introduce yourself plus your company/product, answer their questions as best as you can and if they are frustrated or not willing to talk just as them if they would prefer a call back later.

Do not force someone into being your customer. Keep the call sweet and short.