Don't know who  is this calling?

i got 4 calls one right after another but they never left a voicemail

Got 4 calls one right after the other, did not leave message on voicemail. just hung up,

i also got 4 calls.never a message

I have been getting calls from this number for the past two weeks. They have been calling almost hourly. Sometimes the phone calls would be consecutive. They don't leave a message. Tonight I was on a call which they tried to interrupt by calling and sitting on my call waiting. I researched the number and discovered they are a business in Portland, TX, I hope you could help close their business down. Their phone calls are a nuisance. Thank you.