That is exactly the first thought I had after reading the post. If someone already has the information available in that post, deleting it wouldn't stop them from using it. The only thing it can prevent is letting others gain access to the information.

There is probably no other way for OP to get rid of those calls other than changing his number or any other medium/platform where he receives the calls. It's been more than 11 years now since OP said he made that post in 2013, and I wonder why someone would threaten a random person over the internet after getting their information from somewhere that was posted so long ago. It's a strange world. 

@OP, why are you not changing your number if you are receiving the calls on your phone? Is it impossible to let everyone with that number know you are changing it? This will get rid of the issue.