OnePlan telephone harassment

I made the dreadful mistake of trying to get an online estimate on pet insurance through OnePlan. At no point in time did I click the button to get a call back. Shortly after I had closed the browser, the phone calls started. TruCaller was blocking most as spam, but as many as 8 calls in the day with a variation on the end digits. Eventually, I answered and respectfully asked that I not be contacted again. In only what can be described as harassment, these calls continued, over the weekend, at odd hours. They had even managed to supposedly leave a message, and when I went in to listen to the voice mail, which wasn't there, it automatically dials their number. Again today, I answer and ask that I be removed and reiterate that I did not give permission to be contacted. Not on!