I've been getting same calls

It's Credit One Bank!!! They have been calling me every 1/2 hour for the last 3 days. I answered the first time they called and some guy asked me to verify all kinds of info but he refused to tell me who he was or why he was calling so I hung up. They will call and leave a blank voicemail, I've been getting 10 a day. Finally after 5 calls today between 8:30am and 10am a different guy left a voicemail saying he was calling from Credit One Bank. I do have a credit card with them that is only a week past due and my balance is only $26. I made my payment a few minutes ago and hopefully they will stop calling me...I will get nasty if necessary. I have had this card for 3 years and this is my first late payment...if this is how they are going to be I will close this card and take my money elsewhere. They are also calling from this number 972-969-0198.

They call my cell and my home every 30 minutes.  I wonder if this is even legal?

No!

A debt collector may not engage in any conduct the natural consequence of which is to harass, oppress, or abuse any person in connection with the collection of a debt. Without limiting the general application of the foregoing, the following conduct is a violation of this section:

Causing a telephone to ring or engaging any person in telephone conversation repeatedly or continuously with intent to annoy, abuse, or harass any person at the called number.

https://www.ftc.gov/enforcement/rules/rulemak ... ctices-act-text

I have been receiving calls from this number for the past week or so. Each time I answer, nobody is there. They've left voicemails but nobody says anything. My credit card from this company is not behind in any aspect. This is super frustrating!